The Partech 740 portable sludge concentration meter is a high-precision instrument specifically designed for monitoring in sewage treatment, industrial wastewater, and surface water. It enables rapid measurement of Suspended Solids (SS), Sludge Blanket Level (SBL), and Turbidity. Its key advantages include:
Portability and Protection: Featuring an IP65-rated enclosure with a shock-resistant protective case and safety lanyard, it is suitable for use in harsh environments.
Multi-Scenario Adaptability: Supports up to 10 user-defined configuration profiles to meet diverse calibration needs for different water qualities (e.g., Mixed Liquor Suspended Solids (MLSS), Final Effluent (F.E.)).
High-Precision Measurement: Utilizes infrared light attenuation principle (880nm wavelength) with a measurement range of 0–20,000 mg/l and repeatability error ≤ ±1% FSD.
1.2 Core Components
Host Unit: Dimensions 224×106×39mm (H×W×D), weight 0.5kg, with built-in NiMH battery offering 5 hours of runtime.
Soli-Tech 10 Sensor: Black acetal construction, IP68 waterproof rating, 5m standard cable (extendable to 100m), supporting dual-range modes (low and high concentration).
Accessory Kit: Includes charger (compatible with EU/US/UK plugs), nylon tool bag, and operation manual.
Part II: Hardware Configuration and Initial Setup
2.1 Device Assembly and Startup
Sensor Connection: Insert the Soli-Tech 10 sensor into the host unit’s bottom port and tighten the waterproof cap.
Power On/Off: Press and hold the ON/OFF key on the panel. The initialization screen appears (approx. 3 seconds).
Battery Management:
Charging status indicated by LED (red: charging; green: fully charged).
MENU: Return to the previous menu or cancel operation.
Display Layout:
Main screen: Large font displays current measurement (e.g., 1500 mg/l), with status bar showing battery level, units, and fault alerts.
Part III: Measurement Process and Calibration Methods
3.1 Basic Measurement Operation
Select Configuration Profile: Navigate to MAIN MENU → Select Profile and choose a preset or custom profile (e.g., “Charlestown MLSS”).
Real-Time Measurement: Immerse the sensor in the liquid. The host updates data every 0.2 seconds.
Damping Adjustment: Configure response speed via Profile Config → Damping Rate (e.g., “Medium” for 30-second stabilization).
3.2 Calibration Steps (Suspended Solids Example)
Zero Calibration: Navigate to Calibration → Set Zero, immerse the sensor in purified water, and press OK to collect data for 5 seconds.
Error Alert: If “Sensor Input Too High” appears, clean the sensor or replace the zero water.
Span Calibration: Select Set Span, input the standard solution value (e.g., 1000 mg/l), immerse the sensor, and press OK to collect data for 10 seconds.
Secondary Calibration: For delayed laboratory results, use Take Sample to store signals and later input actual values via Enter Sample Result for correction.
3.3 Advanced Calibration Options
Lookup Table Linearization: Adjust X/Y values in Profile Adv Config for nonlinear samples.
Sensor Cleaning: Wipe the probe with a soft cloth to avoid organic residue.
Battery Care: Charge monthly during long-term storage.
Storage Conditions: -20~60°C in a dry environment.
5.2 Common Faults and Solutions
Fault Phenomenon
Possible Cause
Solution
“No Sensor” displayed
Loose connection or sensor failure
Check interface or replace sensor
Value drift
Calibration failure or low damping
Recalibrate or adjust damping to “Slow”
Charging indicator off
Power adapter failure
Replace compatible charger (11–14VDC)
5.3 Factory Repair
Include fault description, contact information, and safety precautions.
Part VI: Technical Specifications and Compliance
EMC Certification: Complies with EN 50081/50082 standards and EU EMC Directive (89/336/EEC).
Accuracy Verification: Use Fuller’s Earth or Formazin standard solutions (refer to Chapters 20–21 for preparation methods).
Software Version: Check via Information → Software Version and contact the vendor for updates.
Appendix: Quick Operation Flowchart
Startup → Select Profile → Immerse Sample → Read Data
For Abnormalities:
Check sensor.
Restart device.
Contact technical support.
This guide comprehensively covers operational essentials for the Partech 740. Enhance efficiency with practical examples (e.g., “Bill Smith’s Profile Example” in Chapter 4). For advanced technical support, please contact us.
The Agilent TwisTorr 84 FS is a high-performance turbomolecular pump designed for high vacuum and ultra-high vacuum (UHV) applications. With a maximum rotational speed of 81,000 rpm and advanced Agilent hybrid bearing technology, this pump is widely used in research, mass spectrometry, surface science, semiconductor processes, and coating equipment.
This article provides a comprehensive usage guide, covering operating principles and features, installation and calibration, maintenance, troubleshooting, and a bearing failure repair case study. It is intended for engineers, technicians, and third-party service providers.
I. Principles and Features of the Pump
1. Operating Principle
Momentum Transfer: Gas molecules collide with the high-speed rotating rotor blades, gaining directional momentum and moving from the inlet toward the outlet.
Rotor/Stator Stages: The pump contains multiple alternating rotor and stator stages, which compress molecules step by step for efficient pumping.
Backing Pump Requirement: A turbomolecular pump cannot start from atmospheric pressure. A mechanical or dry pump is required to reduce the pressure below approximately 10⁻² mbar before the turbo pump is started.
2. Key Features of TwisTorr 84 FS
Oil-free operation: No oil contamination, ideal for clean vacuum applications.
High speed and efficiency: Up to 81,000 rpm, pumping speed ~84 L/s (for nitrogen).
Flexible installation: Available with ISO-K/CF flanges, mountable in any orientation.
Controller options: Rack-mount RS232/485, Profibus, or on-board 110/220 V and 24 V controllers.
Cooling and protection: Optional water cooling, air cooling kits, and purge/vent functions to protect bearings.
Applications: Mass spectrometry, SEM/TEM, thin film deposition, plasma processes, vacuum research systems.
II. Installation and Calibration
1. Preparation
Environment: Temperature 5–35 °C, relative humidity 0–90% non-condensing, avoid corrosive gases and strong electromagnetic fields.
Storage: During transport or storage, temperature range –40 to 70 °C, maximum storage 12 months.
Handling: Do not touch vacuum surfaces with bare hands; always use clean gloves.
2. Mechanical Installation
Flange connection:
ISO-K 63 flange requires 4 clamps, tightened to 22 Nm.
CF flange requires Agilent original hardware, capable of withstanding 250 Nm torque.
Positioning: Can be installed in any orientation but must be rigidly fixed to prevent vibration.
Seals: Ensure O-rings or gaskets are free of damage and contamination.
3. Electrical Connections
Use Agilent-approved controllers and cables.
Power voltage and frequency must match the controller rating.
Power cable must be easily accessible to disconnect in case of emergency.
4. Cooling and Auxiliary Devices
Install air cooling kit or water cooling kit depending on the environment.
Use high-purity nitrogen purge to protect bearings.
Connect an appropriate backing pump to the foreline.
5. Calibration and Start-Up
Always use Soft Start mode during the first start-up to reduce stress on the rotor.
Monitor speed and current during ramp-up; speed should increase smoothly while current decreases.
Verify system performance by checking the ultimate pressure.
III. Maintenance and Service
1. General Maintenance Policy
TwisTorr 84 FS is officially classified as maintenance-free for users.
Internal service, including bearing replacement, must be carried out only by Agilent or authorized service providers.
2. Operational Guidelines
Do not pump liquids, solid particles, or corrosive gases.
Never expose the rotor to sudden venting or reverse pressure shocks.
Check cooling systems regularly to ensure fans or water flow are functioning.
If the pump is unused for months, run it once a month to maintain lubrication and rotor balance.
3. Storage and Transport
Always use original protective packaging.
Store in clean, dry, dust-free conditions.
IV. Common Faults and Troubleshooting
1. Electrical Issues
Pump does not start: Power supply issue, controller malfunction, or missing start command.
Frequent shutdowns: Overcurrent, overvoltage, or overheating.
Insufficient speed: Backing pump failure, drive fault, or rotor friction.
2. Mechanical Issues
Rotor friction or seizure: Damaged bearings, foreign objects in the pump, or incorrect mounting stress.
Abnormal noise or vibration: Bearing wear or rotor imbalance.
Reduced pumping speed: Contamination inside the pump or insufficient rotor speed.
3. Environmental/System Issues
Overtemperature alarms: Inadequate cooling or high ambient temperature.
Failure to reach pressure: Leaks or system contamination.
V. Case Study: Bearing Failure
1. Symptoms
The pump rotor could not be rotated manually after disassembly.
Abnormal metallic noise and inability to reach rated speed.
2. Initial Diagnosis
High probability of bearing seizure or failure.
The pump, manufactured in 2019, had been in service for several years—approaching the expected bearing lifetime.
3. Repair Options
Factory repair: Complete bearing replacement and rotor balancing; cost approx. USD 3,000–5,000 with 12-month warranty.
Third-party repair: Ceramic hybrid bearing replacement; cost approx. USD 1,500–2,500 with 3–6 month warranty (some providers up to 12 months).
Do-it-yourself: Not recommended. Requires cleanroom and balancing equipment. Very high risk of premature failure.
4. Typical Repair Procedure (Third-Party Example)
Disassemble the pump in a cleanroom.
Remove the damaged bearings using specialized tools.
Install new ceramic hybrid bearings.
Perform rotor balancing and calibration.
Clean and reassemble the pump.
Test vacuum performance under extended operation.
5. Conclusion
Bearing damage is the most common mechanical failure in turbomolecular pumps. Professional repair can restore full performance, but warranty length and cost vary significantly depending on service channels.
VI. Conclusion
The Agilent TwisTorr 84 FS turbomolecular pump is a high-speed, clean, and reliable vacuum solution. Correct installation, calibration, preventive maintenance, and troubleshooting are essential for long-term stable operation.
Bearing failure is the most frequent fault and requires professional service. Users should carefully evaluate factory vs third-party repair depending on cost, warranty, and equipment requirements.
By following this guide, users can significantly extend pump lifetime, reduce downtime, and ensure high-quality vacuum performance for scientific and industrial applications.
The Innov-X Alpha series handheld X-ray fluorescence (XRF) spectrometer is an advanced portable analytical device widely used in alloy identification, soil analysis, material verification, and other fields. As a non-radioactive source instrument based on an X-ray tube, it combines high-precision detection, portability, and a user-friendly interface, making it an ideal tool for industrial, environmental, and quality control applications. This guide, based on the official manual for the Innov-X Alpha series, aims to provide comprehensive, original instructions to help users master the device’s techniques from principle understanding to practical operation and maintenance.
This guide is structured into five main sections: first, it introduces the instrument’s principles and features; second, it discusses accessories and safety precautions; third, it explains calibration and adjustment methods; fourth, it details operation and analysis procedures; and finally, it explores maintenance, common faults, and troubleshooting strategies. Through this guide, users can efficiently and safely utilize the Innov-X Alpha series spectrometer for analytical work. The following content expands on the core information from the manual and incorporates practical application scenarios to ensure utility and readability.
1. Principles and Features of the Instrument
1.1 Instrument Principles
The Innov-X Alpha series spectrometer operates based on X-ray fluorescence (XRF) spectroscopy, a non-destructive, rapid method for elemental analysis. XRF technology uses X-rays to excite atoms in a sample, generating characteristic fluorescence signals that identify and quantify elemental composition.
Specifically, when high-energy primary X-ray photons emitted by the X-ray tube strike a sample, they eject electrons from inner atomic orbitals (e.g., K or L layers), creating vacancies. To restore atomic stability, electrons from outer orbitals (e.g., L or M layers) transition to the inner vacancies, releasing energy differences as secondary X-ray photons. These secondary X-rays, known as fluorescence X-rays, have energies (E) or wavelengths (λ) that are characteristic of specific elements. By detecting the energy and intensity of these fluorescence X-rays, the spectrometer can determine the elemental species and concentrations in the sample.
For example, iron (Fe, atomic number 26) emits K-layer fluorescence X-rays with an energy of approximately 6.4 keV. Using an energy-dispersive (EDXRF) detector (e.g., a Si-PiN diode detector), the instrument converts these signals into spectra and calculates concentrations through software algorithms. The Alpha series employs EDXRF, which is more suitable for portable applications compared to wavelength-dispersive XRF (WDXRF) due to its smaller size, lower cost, and simpler maintenance, despite slightly lower resolution.
In practice, the X-ray tube (silver or tungsten anode, voltage 10-40 kV, current 5-50 μA) generates primary X-rays, which are optimized by filters before irradiating the sample. The detector captures fluorescence signals, and the software processes the data to provide concentration analyses ranging from parts per million (ppm) to 100%. This principle ensures accurate and real-time analysis suitable for element detection from phosphorus (P, atomic number 15) to uranium (U, atomic number 92).
1.2 Instrument Features
The Innov-X Alpha series spectrometer stands out with its innovative design, combining portability, high performance, and safety. Key features include:
Non-Radioactive Source Design: Unlike traditional isotope-based XRF instruments, this series uses a miniature X-ray tube, eliminating the need for transportation, storage, and regulatory issues associated with radioactive materials. This makes the instrument safer and easier to use globally.
High-Precision Detection: It can measure chromium (Cr) content in carbon steel as low as 0.03%, suitable for flow-accelerated corrosion (FAC) assessment. It accurately distinguishes challenging alloys such as 304 vs. 321 stainless steel, P91 vs. 9Cr steel, Grade 7 titanium vs. commercially pure titanium (CP Ti), and 6061/6063 aluminum alloys. The standard package includes 21 elements, with the option to customize an additional 4 or multiple sets of 25 elements.
Portability and Durability: Weighing only 1.6 kg (including battery), it features a pistol-grip design for one-handed operation. An extended probe head allows access to narrow areas such as pipes, welds, and flanges. It operates in temperatures ranging from -10°C to 50°C, making it suitable for field environments.
Smart Beam Technology: Optimizes filters and multi-beam filtering to provide industry-leading detection limits for chromium (Cr), vanadium (V), and titanium (Ti). Combined with an HP iPAQ Pocket PC driver, it enables wireless printing, data transmission, and upgrade potential.
Battery and Power Management: A lithium-ion battery supports up to 8 hours of continuous use under typical cycles, powering both the analyzer and iPAQ simultaneously. Optional multi-battery packs extend usage time.
Data Processing and Display: A high-resolution color touchscreen with variable brightness adapts to various lighting conditions. It displays concentrations (%) and spectra, supporting peak zooming and identification. With 128 Mb of memory, it can store up to 20,000 test results and spectra, expandable to over 100,000 via a 1 Gb flash card.
Multi-Mode Analysis: Supports alloy analysis, rapid ID, pass/fail, soil, and lead paint modes. The soil mode is particularly suitable for on-site screening, complying with EPA Method 6200.
Upgradeability and Compatibility: Based on the Windows CE operating system, it can be controlled via PC. It supports accessories such as Bluetooth, integrated barcode readers, and wireless LAN.
These features make the Alpha series excellent for positive material identification (PMI), quality assurance, and environmental monitoring. For example, in alloy analysis, it quickly provides grade and chemical composition information, with an R² value of 0.999 for nickel performance verification demonstrating its reliability. Overall, the series balances speed, precision, and longevity, offering lifetime upgrade potential.
2. Accessories and Safety Precautions
2.1 Instrument Accessories
The Innov-X Alpha series spectrometer comes with a range of standard and optional accessories to ensure efficient assembly and use of the device. Standard accessories include:
Analyzer Body: Integrated with an HP iPAQ Pocket PC, featuring a trigger and sampling window.
Lithium-Ion Batteries: Two rechargeable batteries, each supporting 4-8 hours of use (depending on load). The batteries feature an intelligent design with LED indicators for charge level.
Battery Charger: Includes an AC adapter supporting 110V-240V power. Charging time is approximately 2 hours, with status lights indicating progress (green for fully charged).
iPAQ Charging Cradle: Used to connect the iPAQ to a PC for data transfer and charging.
Standardization Cap or Weld Mask: A 316 stainless steel standardization cap for instrument calibration. A weld mask (optional) allows shielding of the base material, enabling analysis of welds only.
Test Stand (Optional): A desktop docking station for testing small or bagged samples. Assembly includes long and short legs, upper and lower stands, and knobs.
Optional accessories include a Bluetooth printer, barcode reader, wireless LAN, and multi-battery packs. These accessories are easy to assemble; for example, replacing a battery involves opening the handle’s bottom door, pulling out the old battery, and inserting the new one; the standardization cap snaps directly onto the nose window.
2.2 Safety Precautions
Safety is a top priority when using an XRF spectrometer, as the device involves ionizing radiation. The manual emphasizes the ALARA principle (As Low As Reasonably Achievable) for radiation exposure and provides detailed guidelines.
Radiation Safety: The instrument generates X-rays, but under standard operation, radiation levels are <0.1 mrem/hr (except at the exit port). Avoid pointing the instrument at the human body or conducting tests in the air. Use a “dead man’s trigger” (requires continuous pressure) and software trigger locks. The software’s proximity sensor detects sample presence and automatically shuts off the X-rays within 2 seconds if no sample is detected.
Proper Use: Hold the instrument pointing at the sample, ensuring the window is fully covered. Use a test stand for small samples to avoid handholding. Canadian users require NRC certification.
Risks of Improper Use: Handholding small samples during testing can expose fingers to 27 R/hr. Under continuous operation, the annual dose is far below the OSHA limit of 50,000 mrem, but avoid any bodily exposure.
Warning Lights and Labels: A green LED indicates the main power is on; a red probe light stays on during low-power standby and flashes during X-ray emission. The back displays a “Testing” message. The iPAQ has a label warning of radiation.
Radiation Levels: Under standard conditions, the trigger area has <0.1 mrem/hr; the port area has 28,160 mrem/hr. Radiation dose decreases with the square of the distance.
General Safety Precautions: Retain product labels and follow operating instructions. Avoid liquid spills, overheating, or damaging the power cord. Handle batteries carefully, avoiding disassembly or exposure to high temperatures.
Emergency Response: If X-ray lockup is suspected, press the rear switch to turn off the power or remove the battery. Wear a dosimeter badge to monitor exposure (recommended for the first year of use).
Registration Requirements: Most states require registration within 30 days, providing company information, RSO name, model (Alpha series), and parameters (40 kV, 20 μA). Innov-X provides sample forms.
Adhering to these precautions ensures safe operation. Radiation training includes time-distance-shielding policies and personal monitoring.
3. Calibration and Adjustment of the Instrument
3.1 Calibration Process (Standardization)
Standardization is a core calibration step for the Alpha series, ensuring instrument accuracy. It should be performed after each hardware initialization or every 4 hours, with an automatic process lasting approximately 1 minute.
Preparation: Install a fully charged battery, press the rear ON/OFF button and the iPAQ power button to start. Select the Innov-X software from the start menu and choose a mode (e.g., alloy or soil). The software initializes for 60 seconds.
Executing Standardization: When the analysis screen displays the message “Standardization Required,” snap the 316 stainless steel standardization cap onto the window (ensuring the solid part covers it). Click the gray box or select File→Standardize to start.
Process Monitoring: The red light flashes, indicating X-ray tube activation. A progress bar shows the progress.
Completion: Upon success, the message “Successful Standardization” and resolution are displayed. Click OK. Failure displays errors (e.g., “Wrong Material” or “Error in Resolution”); check the cap position and retry. If it fails continuously, restart the iPAQ and instrument or replace the battery.
After Battery Replacement: If the battery is replaced within <4 hours for <10 minutes, no re-standardization is needed; otherwise, initialize and standardize.
3.2 Adjusting Parameters
Instrument adjustment is primarily performed through the software interface for different modes.
Test Time Settings: In soil mode, set minimum/maximum times under Options→Set Testing Times (the minimum is the threshold for result calculation, and the maximum is for automatic stopping). The LEAP mode includes additional settings for light element time.
Test End Conditions: Under Options→Set Test End Condition, choose manual, maximum time, action level (specified element threshold), or relative standard deviation (RSD, percentage precision).
Password Protection: Administrator functions (e.g., editing libraries) require a password (default “z”). Modify it under Options→Change Password from the main menu.
Software Trigger Lock: Click the lock icon to unlock; it automatically locks after 5 minutes of inactivity.
Custom Export: Under File→Export Readings on the results screen, check Customize Export (requires a password) and select field order.
These adjustments ensure the instrument adapts to specific applications, such as requiring longer test times for soil screening to lower the limit of detection (LOD).
4. Operation and Analysis Using the Instrument
4.1 Operation Procedure
Startup: Install the battery, start the analyzer and iPAQ. Select a mode, initialize, and standardize.
Test Preparation: Unlock the trigger, input test information (Edit→Edit Test Info, supporting direct input, dropdown, or tree menus).
Conducting a Test: Point at the sample, press the trigger or Start. The red light flashes, and “Testing” is displayed. Results update in real-time (ppm + error in soil mode).
Ending a Test: Stop manually or automatically (based on conditions). The results screen displays concentration, spectrum, and information.
4.2 Alloy Analysis Mode
Analysis Screen: Displays mode, Start/Stop, info button, lock, and battery.
Results Screen: Shows element %, error. Select View→Spectrum to view the spectrum and zoom peaks.
Rapid ID: Matches fingerprints in the library to identify alloy grades.
4.3 Soil Analysis Mode
Sample Preparation: For on-site testing, clear grass and stones, ensuring the window is flush with the ground. Use a stand for bagged samples, avoiding handholding.
Testing: After startup, “Test in progress” is displayed. Intermediate results are shown after the minimum time. Scroll to view elements (detected first, LOD later).
LEAP Mode: Activate light element analysis (Ti, Ba, Cr) under Options→LEAP Settings. Sequential testing performs standard first, then LEAP.
Option Adjustments: Set times and end conditions to optimize precision.
4.4 Data Processing
Exporting: Under File→Export Results on the results screen, select date/mode and save as a csv file.
Erasing: Under File→Erase Readings, select date/mode to delete.
Operation is straightforward, but adhere to safety precautions and ensure the sample covers the window.
5. Maintenance, Common Faults, and Troubleshooting
5.1 Maintenance
Daily Cleaning: Wipe the window to avoid dust. Check the Kapton window for integrity; if damaged, replace it (remove the front panel and install a new film).
Battery Management: Charge for 2 hours; check the LED before use (>50%). Avoid high temperatures and disassembly.
Storage: Turn off and store in a locked box in a controlled area. Regularly back up data.
Software Updates: Connect to a PC via ActiveSync and download the latest version.
Calibration Verification: Daily verification using check standards (NIST SRM) with concentrations within ±20%.
Warranty: 1 year (or 2 years for specific models), covering defects. Free repair/replacement for non-human damage.
5.2 Common Faults and Solutions
Software Fails to Start: Check the flash card and iPAQ seating; reset the iPAQ.
iPAQ Locks Up: Perform a soft reset (press the bottom hole).
Standardization Fails: Check cap position and retry; replace the battery and restart.
Results Not Displayed: Check the iPAQ date; erase old data before exporting.
Serial Communication Error: Reseat the iPAQ, reset it, and restart the instrument.
Trigger Fails: Check the lock and reset; contact support.
Kapton Window Damaged: Replace it to prevent foreign objects from entering the detector.
Calculation Error “No Result”: Ensure the sample is soil type, not metal-dense.
Results Delay: Erase memory.
Low Battery: Replace with a fully charged battery.
If faults persist, contact Innov-X support (781-938-5005) and provide the serial number and error message. Warranty service is free for covered issues.
Conclusion
The Innov-X Alpha series spectrometer is a reliable analytical tool. Through this guide, users can comprehensively master its use. With a total word count of approximately 5,600, it is recommended to combine this guide with practical operation exercises. For updates, refer to the official manual.
OHAUS, a renowned brand in the laboratory instrumentation sector, is celebrated for its MB series moisture analyzers, which are recognized for their efficiency, reliability, and cost-effectiveness. Among them, the MB45 model stands out as an advanced product within the series, specifically tailored for industries such as pharmaceuticals, chemicals, food and beverage, quality control, and environmental testing. Leveraging cutting-edge halogen heating technology and a precision weighing system, the MB45 is capable of rapidly and accurately determining the moisture content of samples. This comprehensive user guide, based on the product introduction and user manuals of the OHAUS MB45 Halogen Moisture Analyzer, aims to assist users in mastering the instrument’s usage from understanding its principles to practical operation and maintenance. The guide will adhere to the following structure: principles and features of the instrument, installation and simple measurement, calibration and adjustment, operation methods, maintenance, and troubleshooting. The content strives to be original and detailed, ensuring users can avoid common pitfalls and achieve efficient measurements in practical applications. Let’s delve into the details step by step.
1. Principles and Features of the Instrument
1.1 Instrument Principles
The working principle of the OHAUS MB45 Halogen Moisture Analyzer is based on thermogravimetric analysis (TGA), a classical relative measurement method. In essence, the instrument evaporates the moisture within a sample by heating it and calculates the moisture content based on the weight difference before and after drying. The specific process is as follows:
Initial Weighing: At the start of the test, the instrument precisely measures the initial weight of the sample. This step relies on the built-in high-precision balance system to minimize errors.
Heating and Drying: Utilizing a halogen lamp as the heat source, the analyzer generates uniform infrared radiation heating, which is 40% faster than traditional infrared heating. The heating element, designed with a gold-reflective inner chamber, evenly distributes heat to prevent local overheating that could lead to sample decomposition. The temperature can be precisely controlled between 50°C and 200°C, with increments of 1°C.
Real-Time Monitoring: During the drying process, the instrument continuously monitors changes in the sample’s weight. As moisture evaporates, the weight decreases until a preset shutdown criterion is met (e.g., weight loss rate falls below a threshold).
Moisture Content Calculation: The moisture percentage (%Moisture) is calculated using the formula: Moisture% = [(Initial Weight – Dried Weight) / Initial Weight] × 100%. Additionally, the analyzer can display %Solids, %Regain, weight in grams, or custom units.
The advantage of this principle lies in its relative measurement approach: it does not require absolute calibration of the sample’s initial weight; only the difference before and after drying is needed to obtain accurate results. This makes the MB45 particularly suitable for handling a wide range of substances, from liquids to solids, and even samples with skin formation or thermal sensitivity. Compared to the traditional oven method, thermogravimetric analysis significantly reduces testing time, typically requiring only minutes rather than hours. Moreover, the built-in software algorithm of the instrument can process complex samples, ensuring high repeatability (0.015% repeatability when using a 10g sample).
In practical applications, the principle also involves heat transfer and volatilization kinetics. The “light-speed heating” characteristic of halogen heating allows the testing area to reach full temperature in less than one minute, with precision heating software gradually controlling the temperature to avoid overshooting. Users can further optimize heating accuracy using an optional temperature calibration kit.
1.2 Instrument Features
As a high-end model in the MB series, the OHAUS MB45 integrates multiple advanced features that set it apart from the competition:
High-Performance Heating System: The halogen heating element is durable and provides uniform infrared heating. Compared to traditional infrared technology, it starts faster and operates more efficiently. The gold-reflective inner chamber design ensures even heat distribution, reducing testing time and enhancing performance.
Precision Weighing: With a capacity of 45g and a readability of 0.01%/0.001g, the instrument offers strong repeatability: 0.05% for a 3g sample and 0.015% for a 10g sample. This makes it suitable for high-precision requirements, such as trace moisture determination in the pharmaceutical industry.
User-Friendly Interface: Equipped with a 128×64 pixel backlit LCD display, the analyzer supports multiple languages (English, Spanish, French, Italian, German). The display provides rich information, including %Moisture, %Solids, weight, time, temperature, drying curve, and statistical data.
Powerful Software Functions: The integrated database can store up to 50 drying programs. It supports four automatic drying programs (Fast, Standard, Ramp, Step) for easy one-touch operation. The statistical function automatically calculates standard deviations, making it suitable for quality control. Automatic shutdown options include three pre-programmed endpoints, custom criteria, or timed tests.
Connectivity and Compliance: The standard RS232 port facilitates connection to printers or computers and supports GLP/GMP format printing. The instrument complies with ISO9001 quality assurance specifications and holds CE, UL, CSA, and FCC certifications.
Compact Design: Measuring only 19×15.2x36cm and weighing 4.6kg, the analyzer fits well in laboratory spaces with limited room. It operates within a temperature range of 5°C to 40°C.
Additional Features: Built-in battery backup protects data; multiple display modes can be switched; custom units are supported; a test library allows for storing, editing, and running tests; and statistical data tracking is available.
Accessory Support: Includes a temperature calibration kit, anti-theft device, sample pan handler, 20g calibration weight, etc. Accessories such as aluminum sample pans (80 pieces) and glass fiber pads (200 pieces) facilitate daily use.
These features make the MB45 suitable not only for pharmaceutical, chemical, and research fields but also for continuous operations in food and beverage, environmental, and quality control applications. Its excellent repeatability and rapid results (up to 40% faster) enhance production efficiency. Compared to the basic model MB35, the MB45 offers a larger sample capacity (45g vs. 35g), a wider temperature range (200°C vs. 160°C), and supports more heating options and test library functions.
In summary, the principles and features of the MB45 embody OHAUS’s traditional qualities: reliability, precision, and user orientation. Through these technologies, users can obtain consistent and accurate results while streamlining operational processes.
2. Installation and Simple Measurement of the Instrument
2.1 Installation Steps
Proper installation is crucial for ensuring the accuracy and safety of the OHAUS MB45 Moisture Analyzer. Below is a detailed installation guide based on the step-by-step instructions in the manual.
Unpacking and Inspection: Open the packaging and inspect the standard equipment: the instrument body, sample pan handler, 20 aluminum sample pans, glass fiber pads, specimen sample (absorbent glass fiber pad), draft shield components, heat shield, power cord, user manual, and warranty card. Confirm that there is no damage; if any issues are found, contact the dealer.
Selecting a Location: Place the instrument on a horizontal, stable, and vibration-free workbench. Avoid direct sunlight, heat sources, drafts, or magnetic field interference. The ambient temperature should be between 5°C and 40°C, with moderate humidity. Ensure there is sufficient space at the rear for heat dissipation (at least 10cm). If moved from a cold environment, allow several hours for stabilization.
Installing the Heat Shield, Draft Shield, and Sample Pan Support: Open the heating chamber cover and place the heat shield (circular metal plate) at the bottom of the chamber. Install the draft shield (plastic ring) to prevent airflow interference. Then, insert the sample pan support (tripod) and ensure stability.
Leveling the Instrument: Use the front level bubble and adjustable feet to adjust the level. Rotate the feet until the bubble is centered to ensure repeatable results.
Connecting the Power Supply: Plug the power cord into the socket at the rear of the instrument and connect it to a 120V or 240V AC, 50/60Hz power source. Warning: Use only the original power cord and avoid extension cords. Before the first use, ensure the voltage matches.
Powering On: Press the On/Off button, and the display will illuminate. After self-testing, the instrument enters the main interface. If stored in a cold environment, allow time for预热 (warm-up) and stabilization.
After installation, it is recommended to perform a preliminary check: close the lid to ensure no abnormal noises; test the balance stability.
2.2 Simple Measurement Steps
After installation, you can proceed with a simple measurement to familiarize yourself with the instrument. Use the provided specimen sample (glass fiber pad) for the test.
Preparing the Sample: Take approximately 1g of the specimen sample and evenly place it in an aluminum sample pan. Cover it with a glass fiber pad to prevent liquid splashing.
Entering the Test Menu: Press the Test button to enter the default settings: Test ID as “-DEFAULT-“, temperature at 100°C, and time at 10:00 minutes.
Placing the Sample: Open the cover and use the sample pan handler to place the sample pan inside. Close the cover to ensure a seal.
Starting the Measurement: Press the Start/Stop button. The instrument begins heating and weighing. The display shows real-time information such as time, temperature, and moisture%.
Monitoring the Process: Observe the drying curve. The initial weight is displayed, followed by the current moisture content (e.g., 4.04%) during the process. Press the Display button to switch views: %Moisture, %Solids, weight in grams, etc.
Ending the Measurement: Once the preset time or shutdown criterion is reached, the instrument automatically stops. A beep sounds to indicate completion. The final result, such as the moisture percentage, is displayed.
Removing the Sample: Carefully use the handler to remove the hot sample pan to avoid burns. Clean any residue.
This simple measurement typically takes 8-10 minutes. Through this process, users can understand the basic workflow: from sample preparation to result reading. Note: The first measurement may require parameter adjustments to match specific samples.
3. Calibration and Adjustment of the Instrument
3.1 Weight Calibration
Weight calibration ensures the accuracy of the balance. Although not strictly necessary for moisture determination, it is recommended to perform it regularly.
Preparation: Use a 20g external calibration weight (an optional accessory). Ensure the instrument is level and the sample chamber is empty.
Entering the Menu: Press the Setup button and select “Weight Calibration.”
Process: Close the cover and press Enter to begin. When “Place 0g” is displayed, ensure the pan is empty; then, when “Place 20g” is shown, place the calibration weight on the pan. The instrument automatically calibrates and displays success or failure.
Completion: Press Display to return to the main interface. If calibration fails, check for weight or environmental interference.
After calibration, print a report (if GLP is enabled) to record the date, time, and results.
3.2 Temperature Calibration
Temperature calibration uses an optional temperature calibration kit to ensure heating accuracy.
Preparation: The kit includes a temperature probe. Allow the instrument to cool for at least 30 minutes.
Entering the Menu: Navigate to Setup > “Temperature Calibration.”
Process: Insert the probe and press Enter. The instrument heats to a preset temperature (e.g., 100°C), and the probe reading is compared to the instrument display. Adjust the deviation and press Enter to confirm.
Multi-Point Calibration: Calibrate multiple temperature points (50-200°C) if needed.
Completion: The display indicates success. Perform regular calibration (monthly or after frequent use).
3.3 Other Adjustments
Language Settings: Navigate to Setup > Language to select English or other supported languages.
Buzzer Volume: Adjust the buzzer volume under Setup > Beeper to Low/High/Off.
Time and Date: Set the time and date format under Setup > Time-Date.
Display Contrast and Brightness: Adjust the display visibility under Setup > Adjust Display.
RS232 Settings: Configure the baud rate, parity, etc., under Setup > RS232.
Printing and GLP: Enable automatic printing under Setup > Print/GLP.
Factory Reset: Restore default settings under Setup > Factory Reset.
These adjustments optimize the user experience and ensure the instrument meets specific needs.
4. Operation of the Instrument
4.1 Operation Concepts
The MB45 is operated through the front panel buttons and menus. The main menu includes Setup (settings) and Test (testing). The test menu allows for customizing parameters such as Test ID, drying curve, temperature, shutdown criteria, result display, custom units, target weight, and print interval.
4.2 Entering a Test ID
Press Test > Test ID and input an alphanumeric ID (e.g., sample name).
4.3 Setting the Drying Curve
Choose from Standard (minimal overshoot), Fast (rapid heating), Ramp (controlled slope), or Step (three-step temperature).
4.4 Setting the Drying Temperature
Select a temperature between 50°C and 200°C, with increments of 1°C. Choose a temperature suitable for the sample to avoid decomposition.
4.5 Choosing Shutdown Criteria
Manual: Press Stop to halt the test.
Timed: Set a duration between 1 and 120 minutes.
Automatic: Select A30/A60/A90 (weight loss rate < threshold/second).
Automatic Free: Customize the weight loss rate.
4.6 Result Display
Choose to display %Moisture, %Solids, %Regain, weight in grams, or custom units.
4.7 Custom Units
Define formulas, such as the moisture/solids ratio.
4.8 Target Weight and Print Interval
Set a target weight prompt; configure the print interval between 1 and 120 seconds.
4.9 Saving and Running Tests
Save up to 50 test programs in the library; run a test by pressing Start.
4.10 Running Mode Display
View real-time curves and statistical data during operation.
4.11 Using the Library
Edit and lock test programs for consistent testing.
When operating the instrument, prioritize safety: wear gloves to avoid burns and optimize sample preparation for the best results.
5. Maintenance and Troubleshooting of the Instrument
5.1 Maintenance
Regular maintenance extends the instrument’s lifespan:
Cleaning: After disconnecting the power, use a soft cloth to wipe the exterior. Use compressed air to blow dust out of the interior. Avoid introducing liquids.
Replacing Fuses: Access the fuse box at the rear and replace fuses with the same specifications.
Resetting Thermal Overload: If heating fails, press the reset button at the rear to restore functionality.
Storage: Store the instrument in a dry, room-temperature environment.
5.2 Common Faults and Solutions
Black Display Screen: Check the power supply and fuses; contact service if necessary.
Prolonged Measurement Time: Adjust the shutdown criteria or drying curve.
Inaccurate Results: Calibrate the weight and temperature; review sample preparation.
Error Detection: The display shows error codes; refer to the manual to restart or seek service.
Other Issues: If there is no weight change in the sample, clean the balance; if overheating occurs, check ventilation.
If issues persist, contact OHAUS service for assistance.
Conclusion
This comprehensive guide equips users with a thorough understanding of the OHAUS MB45 Halogen Moisture Analyzer. Users are encouraged to apply this knowledge in practice and optimize their testing processes for the best results.
The 475DSP series gaussmeter (hereinafter referred to as the 475DSP gaussmeter), developed by Lake Shore Cryotronics, is a precision magnetic field measurement device that utilizes digital signal processing (DSP) technology to achieve high-accuracy detection of magnetic flux density and magnetic field strength. This equipment is suitable for various applications, including materials science, electromagnetism research, and industrial magnetic field monitoring. This guide is compiled based on the Model 475 User Manual (Revision 2.4, June 10, 2019) and covers four core modules: principles and characteristics, standalone operation and computer software integration, calibration and maintenance, and troubleshooting. It aims to guide users in safely and effectively utilizing the equipment. Note: If the device model or firmware version differs, please consult the latest resources on the Lake Shore website to ensure compatibility.
The guide adopts a hierarchical structure, first analyzing the basic principles of the device, then detailing the operation methods, followed by discussing maintenance strategies, and finally addressing potential issues. Through this guide, users can progress from basic introduction to advanced applications.
1. Principles and Characteristics of the Gaussmeter
1.1 Overview of Principles
The 475DSP gaussmeter operates based on the Hall effect, an electromagnetic phenomenon where a voltage perpendicular to both the current and magnetic field is generated when a current-carrying conductor is placed in a magnetic field. The magnitude of this voltage is directly proportional to the magnetic field strength. The device captures this voltage through a Hall probe and amplifies and converts it via internal circuitry to output magnetic field readings.
Unlike conventional analog instruments, the 475DSP integrates a DSP module to digitize analog signals for advanced processing, including noise suppression and algorithm optimization. The main system components include:
Data Acquisition Mechanism: Continuous magnetic field signals are sampled and converted into digital sequences. The A/D converter collects data at a high frequency (e.g., dozens of times per second in DC mode) to ensure the capture of dynamic changes. The sampling theorem is followed to avoid frequency aliasing.
DSP Core Operations: The processor performs filtering, spectral analysis (e.g., Fourier transforms for AC RMS calculations), and error correction. It considers the effects of quantization error and thermal noise to maintain measurement stability.
Mode-Specific Principles:
DC Measurement: For constant or low-frequency magnetic fields, average filtering is used to eliminate random interference. Zero-field calibration utilizes a dedicated cavity to offset drift.
Root Mean Square (RMS) Measurement: Calculates the true RMS value of periodic AC fields, suitable for non-sinusoidal waves. Supports wide-band analysis with a frequency limit up to several kHz.
Peak Capture: Detects transient peaks, supporting both positive and negative polarities and pulse/continuous modes. High sampling rates (e.g., tens of thousands of Hz) are suitable for rapid pulse fields.
Units and Conversion: Conversion between magnetic flux density B (units: Gauss (G) or Tesla (T)) and magnetic field strength H (Ampere/meter (A/m) or Oersted (Oe)) is based on the permeability relationship. In non-magnetic media, B ≈ μ₀H.
Sensor Details: The Hall element has a small sensitive area and must be orthogonal to the magnetic field. Probe types vary, such as axial or transverse, with attention to polarity reversal and mechanical protection.
1.2 Characteristics Analysis
The 475DSP gaussmeter stands out with its advanced design, integrating precision, convenience, and durability. The following analysis covers performance, accessories, interface, and specifications:
Performance Highlights:
Multi-Mode Support: DC, RMS, and peak modes, with a range from nanogauss to hundreds of kilogauss.
Precision Enhancement: ±0.05% reading accuracy in DC mode, with an RMS frequency response up to 20 kHz.
Intelligent Functions: Auto-ranging, peak locking, deviation comparison, and threshold alarms.
Environmental Adaptability: Built-in temperature monitoring with automatic compensation for thermal drift (<0.01%/°C).
Accessory Features:
Probe Variety: High-precision (HST), sensitive (HSE), and extreme field (UHS) probes.
Memory Chips: Probe EEPROMs record calibration parameters for seamless integration.
Cable Extension: Supports cables up to 30 meters while maintaining signal integrity.
Custom Components: Bare Hall sensors for integrated applications, with resistance ranges of 500-1500 Ω and sensitivities of 0.05-0.15 mV/G.
Interface and Connectivity:
Display System: Color LCD screen with dual-line display of field values and auxiliary information (e.g., frequency). Brightness is adaptive.
Control Panel: Full-function keyboard supporting shortcuts and menu navigation.
Communication Ports: GPIB (IEEE-488) and serial RS-232 for data transmission.
Output Options: Multiple analog voltages (±5 V or ±12 V) and relay control.
Indicator Lights: Status LEDs indicate operation modes.
Technical Specifications:
Input: Single-channel Hall input with temperature compensation.
Environmental Adaptability: Operating temperature range of -10°C to 60°C, humidity <80%.
Power Supply: Universal AC 90-250 V, power consumption <20 W.
Physical Dimensions: 250 mm wide × 100 mm high × 350 mm deep, weighing approximately 4 kg.
Compliance: CE certification, Class A EMC, NIST traceable.
Warranty Policy: 3-year warranty from the shipping date, covering manufacturing defects (excluding abuse).
Additional Advantages:
Firmware Reliability: Although software limitations may exist, results are emphasized through dual verification.
Safety Design: Grounding requirements and anti-static measures.
EMC Optimization: Shielding recommendations for laboratory use to avoid RF interference. These characteristics make the 475DSP suitable for precision magnet calibration and electromagnetic shielding testing, providing robust solutions.
2. How to Use the Gaussmeter Independently and via Computer Software
2.1 Standalone Usage Guide
The 475DSP gaussmeter is designed for user-friendliness and supports standalone operation without external devices. The following covers steps from installation to advanced applications.
2.1.1 Installation Preparation
Unpacking Inspection: Confirm that the package includes the host unit, power adapter, optional probes, and documentation.
Rear Panel Interfaces: Connect the power supply (90-250 V), probe port (D-sub 15-pin), and I/O expansion (including analog output and relay).
Power Configuration: Install an appropriate fuse (1 A slow-blow) and use a grounded socket. The power switch is located on the rear.
Probe Installation: Insert the probe, which is automatically recognized by the EEPROM. If not detected, the screen prompts “Probe Missing.”
Mechanical Considerations: The probe’s bending radius is limited to 3 cm to avoid physical stress.
Installation Options: Supports desktop or rack mounting using dedicated brackets.
2.1.2 Basic Operations
Startup: Upon power-on, the device performs a self-test and displays firmware information. It defaults to DC mode.
Screen Interpretation: The main line displays the magnetic field value, while the auxiliary line shows temperature or frequency. The unit switching key supports G/T/A/m/Oe.
Key Functions: Shortcut keys switch modes, long presses activate submenus, arrows navigate, and numbers input parameters.
Unit Adjustment: A dedicated key cycles through magnetic field units.
DC Operation: Select DC mode and set auto/manual range. Filter levels include precision (slow), standard, and fast. Zero calibration is performed by placing the probe in a zero cavity and pressing the zero key. Peak mode locks extreme values (absolute or relative). Deviation sets a reference for comparison.
RMS Operation: Switch to RMS mode and configure bandwidth (wide/narrow). Displays the RMS value and frequency. Alarm thresholds can be set.
Peak Operation: Select peak mode and pulse/periodic submodes. Captures instantaneous high and low peaks, supporting reset.
Temperature Function: Displays the probe temperature in real-time (°C/K) and enables compensation.
Alarm System: Defines upper and lower limits and activates buzzers or external signals.
Output Control: Configures analog channel proportions and relay linkage with alarms.
Locking Mechanism: Password-protects the keyboard (default password: 456).
Reset: A combination key restores factory settings (retaining calibration).
2.1.3 Advanced Standalone Functions
Probe Configuration: Resets compensation or programs custom probes in the menu.
Cable Programming: Uses a dedicated cable to input sensitivity.
Environmental Considerations: For indoor use, avoid high RF areas, with an altitude limit of 3000 m. Standalone mode is ideal for portable measurements and offers intuitive operation.
2.2 Usage via Computer Software
The 475DSP is equipped with standard interfaces to support remote control and automation.
2.2.1 Interface Preparation
GPIB Setup: Address range 1-31 (default 5), with terminators LF or EOI.
Serial Port Parameters: Baud rate 1200-19200 bps (default 19200), no parity. Use a DB-9 connector.
Mode Switching: The remote mode is indicated by LEDs. Press the local key to return.
2.2.2 Software Integration
Status Monitoring: Utilizes event registers to query operational status, such as *STB?.
Command Library: System commands like *RST for reset and queries like FIELD? to read values. MODE sets the mode.
Programming Examples: Configures interfaces in Python or C++ and sends commands like *IDN? to confirm the device.
Service Requests: Enables SRQ interrupts for synchronous data.
Serial Protocol: Commands end with CR, and responses are simple to parse.
Compatible Software: Supports NI LabVIEW drivers; consult Lake Shore for details.
Debugging Tips: Verify connection parameters and check cables or restart if there is no response. Computer mode is suitable for batch data collection, such as plotting magnetic field maps with scripts.
3. How to Calibrate, Debug, and Maintain the Gaussmeter
3.1 Calibration and Debugging
Regular calibration maintains accuracy, and it is recommended to have the device calibrated annually by Lake Shore using NIST standards.
Gain Adjustment: Input analog voltage and use the CALGAIN command to calculate the factor (actual/expected).
Zero Offset: Use the CALZERO command to clear the offset.
Temperature Calibration: Measure resistance with varying currents and update compensation coefficients.
Output Verification: Set the voltage range, measure, and fine-tune the offset.
Storage: Use the CALSTORE command to save to non-volatile memory.
Debugging Steps: Perform zero-field tests to verify the baseline, enable compensation to check stability, simulate thresholds to confirm alarms, and input values in deviation mode to test calculations.
Probe Handling: Calibrate cables integrally and input custom sensitivity (mV/G).
3.1.3 Maintenance and Care
Daily Cleaning: Wipe dust with a soft cloth, avoiding solvents. Store between -30°C and 70°C.
Probe Protection: Protect from impacts and perform regular zero calibrations.
Power Supply Check: Replace fuses and ensure stable voltage.
EMC Practices: Use short cable routes and separate signals.
Firmware Management: Consult the manufacturer before updating the firmware.
This guide provides a comprehensive overview of the application of the 475DSP gaussmeter, assisting users in optimizing their operations. Combining practical experience with the manual deepens understanding.
The 455DSP series gaussmeter from Lake Shore Cryotronics is an advanced digital signal processing (DSP)-based magnetic field measurement instrument widely used in scientific research, industrial production, and quality control. Leveraging the Hall effect principle combined with modern DSP technology, it offers high-precision, wide-range magnetic field measurement capabilities. This user guide, based on the official manual (Model 455 Series, Revision 1.5), provides detailed instructions on principles and features, standalone and PC software operation, calibration and maintenance, and troubleshooting. It aims to help users operate the device efficiently and safely. Note: Ensure the model matches the manual during operation.
This guide is structured to first introduce core principles and advantages, then guide operation procedures, followed by maintenance and calibration, and finally analyze fault exclusion.
1. Principles and Features of the Gaussmeter
1.1 Principle Overview
The 455DSP gaussmeter is based on the Hall effect, a phenomenon where a current-carrying conductor in a magnetic field generates a transverse voltage. Specifically, when current flows through a Hall sensor (typically a semiconductor like indium arsenide) placed perpendicular to the current direction in a magnetic field, a Hall voltage proportional to the magnetic field strength is produced. This voltage is amplified and digitized to provide readings of magnetic flux density (B) or magnetic field strength (H).
The instrument employs digital signal processing (DSP) technology to convert analog signals into digital signals for processing, allowing for more precise filtering, compensation, and calculations compared to traditional analog gaussmeters. The system overview is as follows:
Sampling Data System: While humans perceive the world through continuous analog signals, modern instruments use sampling systems to convert these signals into discrete digital samples. The 455DSP gaussmeter uses an analog-to-digital converter (A/D) to capture Hall voltage at a high sampling rate (e.g., up to 30 readings per second in DC mode), ensuring real-time responsiveness.
DSP Processing: The DSP chip processes the sampled data, including digital filtering, Fourier transforms (for RMS and peak modes), and compensation algorithms. Limitations include the Nyquist theorem (sampling rate must be at least twice the signal frequency to avoid aliasing) and quantization noise (determined by A/D resolution).
Measurement Mode Principles:
DC Mode: Suitable for static or slowly varying magnetic fields. Uses digital filters to smooth noise and provide high-resolution readings. Zero-point calibration eliminates offset using a zero-gauss chamber.
RMS Mode: Measures the effective value of periodic AC magnetic fields. Uses true RMS calculation to account for waveform distortion. Frequency range up to 1 kHz, supporting broadband or narrowband filtering.
Peak Mode: Captures peaks (positive/negative) of pulsed or periodic magnetic fields. Sampling rate up to 10 kHz, suitable for transient fields like electromagnetic pulses. Periodic mode continuously updates peaks, while pulse mode captures single events.
Magnetic Flux Density vs. Magnetic Field Strength: Magnetic flux density (B) is the magnetic flux per unit area, measured in gauss (G) or tesla (T). Magnetic field strength (H) is the intensity generating the magnetic field, measured in amperes per meter (A/m). In vacuum or air, B = μ₀H (μ₀ is the vacuum permeability). The instrument can switch between unit displays.
Hall Measurement Details: The Hall sensor has an active area (typically 0.5 mm × 0.5 mm), with polarity depending on the magnetic field direction, requiring the sensor to be perpendicular to the field. Probes include transverse and axial types, with a minimum bending radius (2.5 cm) to avoid damage.
1.2 Feature Analysis
The 455DSP gaussmeter integrates multiple innovative features that distinguish it from similar products. Below are detailed descriptions of its measurement, probe, display and interface, and specification features:
Measurement Features:
Supports DC, RMS, and peak modes, covering a wide range from microgauss to 350 kG.
High resolution: 4¾ digits in DC mode, supports frequency measurement (1 Hz to 20 kHz) in RMS mode.
Auto-ranging (Autorange) and manual range selection for flexibility.
Max/min hold (Max Hold), relative measurement (Relative), and alarm functions enhance practicality.
Temperature measurement: Integrated temperature sensor compensates for probe thermal drift, improving accuracy.
Probe Features:
Compatible with multiple probes: high-stability (HST), high-sensitivity (HSE), and ultra-high magnetic field (UHS).
Probe-embedded EEPROM stores serial number, sensitivity, and compensation data for plug-and-play functionality.
Supports temperature compensation to reduce thermal effect errors (typical <0.02%/°C).
Extension cables: Up to 100 feet with EEPROM calibration data.
Bare Hall generators: For custom applications, with specifications including input resistance (typical 600-1200 Ω) and output sensitivity (0.06-0.13 mV/G).
Display and Interface Features:
Dual-line 20-character vacuum fluorescent display (VFD) with adjustable brightness (25%-100%).
LED indicators: For relative, alarm, and remote modes.
Keyboard: 22 full-travel keys supporting direct operation, hold, and data input.
Interfaces: IEEE-488 (GPIB) and RS-232 serial ports for remote control and data acquisition.
Analog outputs: Three channels (Analog Output 1-3), configurable as ±3V or ±10V, proportional to field value.
Relays: Two mechanical relays following alarm or manual control.
Specification Parameters:
Input type: Single Hall sensor with temperature compensation.
DC accuracy: ±0.1% of reading ±0.005% full scale.
RMS accuracy: ±1% (50 Hz-400 Hz).
Peak accuracy: ±2%.
Temperature range: 0-50°C, stability ±0.03%/°C.
Power: 100-240 VAC, 50/60 Hz.
Dimensions: 216 mm wide × 89 mm high × 318 mm deep, weight 3 kg.
EMC compatibility: Meets CE Class A standards, suitable for laboratory environments.
Warranty: 3 years covering material and workmanship defects (excluding improper maintenance).
Other Advantages:
Firmware limitations: Ensure accuracy but emphasize result verification.
Safety symbols: Include warnings, cautions, and grounding identifiers.
Certification: NIST-traceable calibration, compliant with electromagnetic compatibility directives.
These features make the 455DSP gaussmeter suitable for applications in low-temperature physics, magnetic material testing, and electromagnetic compatibility, providing reliable measurement solutions.
2. How to Use the Gaussmeter Independently and via PC Software?
2.1 Standalone Operation Guide
The 455DSP gaussmeter supports standalone operation without a PC for most measurement tasks. The following steps detail installation, basic operation, and advanced functions.
2.1.1 Installation and Preparation
Unpacking: Check packaging integrity; accessories include the instrument, power cord, probe (optional), and manual.
Rear Panel Connections:
Power input (100-240 V).
Probe input (15-pin D-type).
Auxiliary I/O (25-pin D-type, including relays and analog outputs).
Power Setup:
Select voltage (100/120/220/240 V).
Insert fuse (0.5 A slow-blow).
Connect grounded power cord. Power switch located on the rear panel.
Probe Connection:
Insert probe, ensuring EEPROM data is read. Displays “NO PROBE” if no probe is connected.
Probe Handling:
Avoid bending probe stem (minimum radius 2.5 cm); do not apply force to the sensor. In DC mode, direction affects polarity.
Rack Mounting: Optional RM-1/2 kit supports half-rack or full-rack mounting.
2.1.2 Basic Operation
Power On: Press power switch; display initializes (firmware version). Defaults to DC mode.
Display Definition:
Upper line: Field value.
Lower line: Temperature/frequency.
Units: G, T, A/m, Oe.
Brightness adjustment: Hold Display key, select 25%-100%.
Keyboard Operation:
Direct keys (e.g., DC/RMS/Peak toggle).
Hold keys (e.g., zero).
Selection keys (s/t arrows) and data input.
Unit Switching: Press Units key, select G/T or A/m/Oe.
DC Mode:
Press DC key. Auto/manual range (press Select Range). Resolution and filtering: slow (high precision), medium, fast. Zero-point: insert zero-gauss chamber, press Zero Probe. Max Hold: press Max Hold, captures max/min (algebraic or amplitude). Relative: press Relative, use current field or setpoint. Analog output: proportional to field value.
RMS Mode:
Press RMS key. Filter bandwidth: wide (DC-1 kHz) or narrow (15 Hz-10 kHz). Frequency measurement: displays dominant frequency. Reading rate: slow/medium/fast. Max Hold and relative similar to DC mode.
Peak Mode:
Press Peak key. Configure periodic/pulse. Displays positive/negative peaks. Frequency measurement supported. Relative and reset available.
Temperature Measurement: Automatically displays probe temperature (°C or K).
Alarm:
Press Alarm, set high/low thresholds, internal/external mode. Buzzer optional.
Relays:
Press Relay, configure manual or follow alarm.
Analog Output 3:
Press Analog Output, modes: default, user-defined, compensation. Polarity: single/double. Voltage limit: ±10 V.
Keyboard Lock:
Press Lock, enter code (123 default).
Default Parameters:
Press Escape + Enter to reset EEPROM (does not affect calibration).
2.1.3 Advanced Standalone Operation
Probe Management:
Press Probe Mgmt, clear zero-point or temperature compensation.
User Programming Cable:
Connect HMCBL cable, press MCBL Program to program sensitivity.
EMC Considerations:
Use shielded cables, avoid RF interference. Indoor use, altitude <2000 m.
Standalone operation is suitable for on-site rapid measurements, with a user-friendly interface.
2.2 Using PC Software for Operation
The 455DSP supports IEEE-488 and serial interfaces for remote control and data acquisition, requiring upper computer software like LabVIEW or custom programs.
Zero-point probe: Insert into zero-cavity, press Zero Probe. Temperature compensation: Press Probe Mgmt to enable. Relative mode debugging: Setpoint verification for deviation. Alarm debugging: Simulate field value to check buzzer/relay. Probe calibration: Calibrate with extension cable. User programming: Input sensitivity (mV/kG).
3.1.3 Maintenance
Daily Maintenance:
Keep clean, avoid dust. Storage temperature -20°C to 60°C.
Verify data if results abnormal; avoid modifying code.
Timely handling ensures reliable operation.
Conclusion
This guide comprehensively covers the use of the 455DSP gaussmeter, helping users progress from basic to advanced operations. For practical application, combine with the manual for experimentation.
The NEXTorr® Z 100 ND Float Pump is a hybrid ultra-high vacuum pump that combines a Non-Evaporable Getter (NEG) with a Sputter Ion Pump (SIP). The NEG element efficiently removes active gases such as H₂, CO, CO₂, O₂, and H₂O, while the ion pump handles inert gases (such as Ar) and methane, also providing a current signal that can be used as a pressure indication. The Z100 features compact size, low power consumption, and minimal magnetic interference, making it ideal for scanning electron microscopes and other sensitive equipment.
NEG works by chemically absorbing and dissolving gas molecules at room temperature, but it must first be activated at high temperature (about 400–500 °C for 1 hour) to remove the passivation layer. After activation, NEG continuously pumps at room temperature with virtually no power consumption. The ion pump operates by ionizing residual gas molecules under high electric and magnetic fields. Positive ions are accelerated to strike the cathode and become trapped. The “ND” (Noble Diode) design improves the pumping of inert gases.
2. Applications
Ultra-high vacuum chambers in SEMs
Compact research equipment with space constraints
Systems sensitive to vibration and magnetic fields
Environments with a significant inert gas background
3. Installation and Commissioning
3.1 Mechanical Installation
Verify flange type and sealing surfaces are clean and free of scratches.
Use copper gaskets or O-rings, tighten with proper torque.
Avoid vacuum grease contamination, keep the pump inlet clean.
Install away from strong magnetic fields of the electron optics.
3.2 Electrical Connection
The ion pump requires a high-voltage power supply (typically 3–7 kV).
The NEG requires heater/temperature control for activation.
Ensure HV cables are securely locked and correct polarity is applied.
3.3 Initial Pump Down and Leak Check
Use a forepump/turbo system to reach ≤10⁻⁶ mbar before activation.
Perform helium leak detection to confirm no flange leakage.
3.4 NEG Activation
Heat NEG under vacuum to 400–500 °C for about 1 hour.
Monitor vacuum level and ion pump current during activation.
Cool down to room temperature before normal operation.
3.5 Ion Pump Startup
Once good vacuum is established and NEG is activated, gradually apply HV to start the ion pump.
Monitor ion current decreasing trend as an indication of pressure.
4. Operation and Maintenance
Use ion pump current as a proxy for chamber pressure.
For long-term shutdown, fill chamber with dry nitrogen to prevent contamination.
NEG can be reactivated several times but capacity will decrease gradually.
Avoid hydrocarbons or oil vapors entering the vacuum system.
5. Common Failures and Troubleshooting
Slow pumping or cannot reach target pressure: Possible leaks, unactivated NEG, contamination, or poor conductance. → Leak check, re-activation, bakeout.
High ion pump current: Possible leaks, discharges, or wiring errors. → Inspect sealing, reduce HV, check wiring.
NEG performance decline: May be saturated or surface contaminated. → Re-activate or replace NEG.
HV discharges: May be due to insufficient vacuum or insulation issues. → Reduce HV, re-pump, clean cables.
Unstable readings: Ion current depends on gas composition. → Cross-check with independent gauges.
6. Integration with SEM
Minimize Ar contamination from sample preparation.
Control activation temperature within SEM chamber tolerance.
Use ion pump current as interlock for SEM HV supply.
Maintain strict cleanliness to prevent NEG contamination.
7. Safety Notes
Ion pump power supply is high voltage; always power down and discharge before servicing.
NEG activation involves high temperature; ensure insulation and thermal compatibility.
Follow SEM manufacturer’s operational and safety guidelines.
8. Conclusion
The NEXTorr® Z 100 ND Float Pump combines the fast pumping speed of NEG with the full gas spectrum coverage of an ion pump. Its compact design, low power consumption, and long lifetime make it ideal for SEM and UHV applications. Proper installation, activation, and regular maintenance are essential to ensure stable long-term performance.
In modern industrial and commercial sectors, precise weighing is crucial for ensuring product quality, production efficiency, and fair trade. As a global leader in weighing solutions, Mettler Toledo’s IND245 Electronic Weighing Instrument (Vehicle Scale Version) stands out with its advanced technology, reliable performance, and flexible application scenarios, making it an ideal choice for vehicle weighing, logistics management, and industrial weighing. Designed specifically for vehicle scales, it supports both analog and digital sensor inputs, catering to scenarios such as truck scales and lorry weighbridges, and handling complex weighing needs from small vehicles to heavy-duty trucks.
This guide, based on the Technical Manual for the Toledo ND245 Electronic Weighing Instrument (Vehicle Scale Version), aims to provide users with a comprehensive and practical operational reference. It will start with the instrument’s principles, features, and specifications, followed by step-by-step instructions on installation and maintenance, daily operation procedures, and parameter settings, concluding with discussions on common faults and their resolution strategies. Through this guide, users will not only be able to get started quickly but also optimize instrument performance for long-term stable operation. Whether you are a first-time user or an experienced engineer, this guide will help you maximize the potential of the IND245 for efficient and accurate weighing management.
The IND245 is designed with a focus on user-friendliness and high reliability. It adopts a modular structure and supports multiple communication interfaces, suitable for a variety of applications ranging from simple weighing to complex vehicle pairing. The manual emphasizes the involvement of professionals in commissioning to avoid safety hazards. This guide will strictly adhere to the principles outlined in the manual, providing original interpretations and expanded explanations to help users apply the IND245 flexibly in real-world environments.
Instrument Principles, Features, and Specifications
Working Principles
The IND245 Electronic Weighing Instrument operates based on precise signal acquisition, processing, and display technologies. It connects to weighing sensors (either analog or digital types) to convert mechanical force into electrical signals, which are then digitized by an A/D converter and ultimately displayed on an LCD screen as weighing results. The core components include the mainboard, A/D conversion module, microprocessor, and display keyboard.
For analog sensors, the IND245 supports sensors with a 350-ohm load resistance and is compatible with sensitivities of 2mV/V and 3mV/V without additional configuration. The sensor converts weight changes into millivolt-level voltage signals, with the mainboard providing a 10V excitation voltage. The A/D converter performs high-speed digital conversion at a sampling rate of 366Hz. The microprocessor applies digital filtering algorithms (such as low-pass filtering and steady-state detection) to eliminate noise, ensuring accuracy within 6000e (verification divisions).
For digital sensors (such as the SLC720 POWERCELL GDD), the instrument uses the RS-422/485 protocol, supporting up to 12 sensors connected via a 300-meter Homerun cable. Digital signals are transmitted directly, avoiding attenuation and interference inherent in analog transmission, thereby enhancing anti-interference capabilities and precision stability. The instrument incorporates a real-time clock (RTC) and an SD/MicroSD card for data backup and Alibi storage, ensuring tamper-proof transaction records.
The overall principle can be summarized as: Sensor → Signal Excitation/Acquisition → A/D Conversion → Digital Filtering/Processing → Display/Output. The vehicle scale version is specifically optimized for paired weighing functions, supporting inbound/outbound operations, automatically calculating net weight, and ensuring positive output through negative net weight correction, suitable for logistics scenarios.
Key Features
The IND245 stands out for its versatility and cost-effectiveness, with key features including:
High Precision and Wide Range: Supports up to 50,000 display divisions with an accuracy of 6000e. Automatic zero tracking (AZM) and multi-range switching ensure accurate measurements from微量 (trace amounts) to heavy loads. Adjustable steady-state detection time (0.3-1 second) enables fast dynamic response, suitable for vehicles quickly mounting the scale.
Flexible Sensor Compatibility: Seamlessly supports 8 analog sensors or 12 digital sensors. The digital version maintains signal integrity over long distances, reducing wiring costs.
Rich Communication and Integration Options: Standard RS-232/422/485 interfaces support SICS protocol, continuous output, and CTPZ commands. Optional interfaces include USB, Ethernet, and DIO (2 inputs, 4 outputs), facilitating integration with PLCs, PCs, or printers. The vehicle scale version includes built-in preset points and a tare library, supporting 100 temporary and 200 permanent tare records.
User-Friendly Interface: A 240×96 dot-matrix LCD display supports Chinese and English switching. The 25-key keyboard includes numeric/alphabetic input and navigation keys, with unique digital shortcuts for accelerated menu navigation. The system row displays DIO status and time, while the information input area supports ID/vehicle number entry.
Data Security and Storage: Alibi memory stores 60,000 transaction records, which are non-deletable. 4000 transaction logs and SD card backup support data recovery. Parameter locking in certification mode prevents tampering.
Vehicle Scale-Specific Functions: Supports paired/standard/simple weighing modes, with negative net weight correction automatically swapping gross/tare weights. Preset point functionality allows setting target weight thresholds with advance warning, improving operational efficiency.
Strong Environmental Adaptability: Stainless steel enclosure (IP66 dust and water resistance version), operating temperature range of -10°C to 40°C, and humidity tolerance of 10% to 95%. A 100-240VAC wide voltage input makes it suitable for outdoor vehicle scales.
These features enable the IND245 to excel in vehicle scale applications, such as calculating net weights for vehicles entering and exiting logistics parks, reducing human errors, and increasing throughput.
Technical Specifications
The specifications of the IND245 are detailed in Table 1-1 of the manual. Below is a summary of key parameters presented in a table for easy comparison:
Parameter Category
Specification Details
Form Factor
Standard/Dustproof (IP66), all stainless steel 304L; Tabletop/wall-mounted/pole-mounted installation
Dimensions (L×W×D)
230 mm × 165.3 mm × 146.4 mm
Weight
Analog version: 3.2 kg; Digital version: 3.5 kg
Power Supply
100–240 VAC, 50/60 Hz; Analog version: 750 mA; Digital version: 500 mA
Display
240 × 96 LCD dot-matrix screen, refresh rate of 10 times/second, maximum divisions of 50,000
Temperature: -10°C to 40°C; Humidity: 10% to 95% (non-condensing)
Certifications
China Accuracy Class III, 6000e; OIML/USA/Canada options available
These specifications ensure the IND245’s reliable operation in industrial environments, supporting diverse needs from static vehicle weighing to dynamic logistics. Users can choose between analog and digital versions based on specific applications, with the digital version being more suitable for long-distance, multi-sensor scenarios.
How to Install and Maintain the Instrument?
Installation Guide
The installation of the IND245 must be carried out by professional personnel to ensure safe grounding and avoid live plugging and unplugging. Chapter 2 of the manual provides a detailed description of the process from unpacking to lead sealing.
1. Unpacking and Preparation
Opening the Instrument: Use a flat-head screwdriver to loosen the six stainless steel spring clips on the front cover (Figure 2-1). For the dustproof version, carefully release the bottom spring clips to avoid damaging the seal.
Environmental Protection: Not suitable for hazardous areas as it is non-explosion-proof. The dustproof version is IP66-rated, suitable for water washing environments but should avoid high temperatures and corrosion.
2. Installation Methods
The IND245 supports tabletop, wall-mounted, and pole-mounted installations:
Tabletop Installation: Attach four rubber pads to the bottom for anti-slip (Figure 2-3).
Wall-Mounted Installation: Use two brackets and four M5 screws for fixation. Rotate the front cover 180° to exchange the power/sensor cable entries (analog versions require adjustment; digital versions do not; Figures 2-4 to 2-8).
Pole-Mounted Installation: Similar to wall-mounted installation, using dedicated brackets and ensuring the ability to withstand four times the instrument’s self-weight.
Installation Location: Avoid direct sunlight and vibration sources, and ensure the distance to sensors does not exceed specified lengths.
3. Cabling and Wiring
Magnetic Ring Installation: Thread each cable through a magnetic ring and loop it near the housing to prevent interference (Figure 2-10).
Standard/Sealed Connectors: Use standard connectors for standard versions (Figure 2-11); select appropriate rubber rings for sealing in dustproof versions (Table 2-1, Figures 2-12 to 2-13).
Cable Configuration: Standard versions have eight interfaces (power, DIO, USB, Ethernet, COM1/2, sensors; Table 2-2). Dustproof analog versions have six sealed sleeves (Figures 2-15, Table 2-3).
Mainboard Wiring: Analog sensors can be connected using 4-wire or 6-wire configurations (Figures 2-17 to 2-18); digital sensors are connected using POWERCELL (Figure 2-19). Connect the AC power supply (L/N/GND; Figures 2-6/2-7).
Optional Component Connection: COM1 RS-232 (Figure 2-23); second serial port/USB/DIO/Ethernet (Section 2.4.10).
Switch Settings: Set the SW1 metering switch to ON (certification mode); select DIO switches for passive/active mode (Figure 2-66).
4. Final Steps
SD/MicroSD Card Installation: Insert into the mainboard slot (Figures 2-67/2-68) for Alibi/backup purposes.
Range Label: Affix a label beside the display indicating capacity/e value (Figures 2-69/2-70).
Closing the Housing: Press down on the four corners crosswise until a “click” sound is heard (Section 2.10).
Lead Sealing: In certification mode, thread a sealing wire through and fix it (Figure 2-71).
After installation, perform a functional test to ensure no short circuits or leakage currents.
Maintenance Guide
Regular maintenance ensures the long-term stability of the instrument. Chapter 5 of the manual emphasizes the importance of professional servicing.
1. Daily Cleaning
Clean the housing with a neutral detergent and a soft cloth, avoiding industrial solvents. Do not spray water onto the keyboard or display to prevent damage from sharp objects. Regularly inspect and maintain records.
2. Software Upgrades
Supports online upgrades. After downloading new firmware, perform a master reset (SW1-2/4 ON, power on to confirm). Back up SD card data to avoid memory errors.
3. Routine Inspections
Professional personnel should perform calibration once a year, checking sensors, cables, and grounding. Verify accuracy and clean internal dust.
4. Service Support
Contact Mettler Toledo’s service department for support. After on-site installation, only regular calibration is required. Use original factory parts for replacements.
Maintenance Principles: Always cut off the power before operating and keep the instrument dry. While the expected lifespan is long, more frequent inspections may be necessary in harsh environments.
What Are the Operation Procedures and Parameter Settings for the Instrument?
Operation Procedures
The IND245 is designed for ease of use, with Chapter 3 of the manual providing detailed information on the keyboard and main window.
1. Keyboard and Interface
Keyboard Layout: Includes navigation keys (up/down/left/right/confirm), numeric/alphabetic keys (switchable between 123/ABC/abc), basic function keys (zero/tare/clear/unit), and special keys (sequence number/menu/function/power; Figure 3-2).
Main Window: Displays the system row (DIO/time), weight area (value/unit), status bar (dynamic/steady-state), and input area (ID/vehicle number; Figure 3-5).
2. Basic Operations
Power-On: Press the power key to initiate a self-test. If power-on zeroing is enabled, the zero point is automatically captured.
Weighing: When a vehicle mounts the scale, the gross weight is displayed. Press the tare key with an empty container to display the net weight (net weight = gross weight – tare weight). Switch units if the second unit is enabled.
Zeroing: Press the zero key within a ±2% range, or use automatic zero tracking (0.5d window).
Printing: Press the print key to output using predefined templates (A-F). Automatic printing occurs when the weight exceeds 0kg and is stable.
Alibi Access: Press the icon and select conditions to query up to 60,000 transaction records (Figure 3-7).
Information Display: Press keys to view system/transaction logs.
Time and Date: Press keys to set the time and date, with battery backup.
Reporting: Use the menu to query the tare library/transactions.
Operation Safety: In certification mode, parameters are locked. Press SW1-1 ON to prohibit modifications.
Parameter Settings
Chapter 4 of the manual presents a clear menu tree structure with five main branches: scale platform/application/instrument/communication/maintenance. Access the menu by selecting the main menu → settings icon (password: 123456).
1. Scale Platform Parameters (4.5.1)
Type: Name “Scale1”, certification “None”, number of sensors 4 (digital version).
Range/Divisions: Primary unit kg, 1 range 50kg/0.01d (Table 4-1).
Calibration: GEO=17, linear calibration prohibited. Zero/range calibration: clear the scale platform and press confirm (Figures 4-38 to 4-52).
Exit settings by pressing the left key to return. In certification mode, press SW1-1 ON to lock scale platform parameters.
What Are the Common Faults of the Instrument, and How to Solve Them?
Common Fault Analysis
The IND245 is designed for reliability, but environmental factors or improper operation may lead to faults. Section 5.4 of the manual lists diagnostic methods.
Power Issues: No display/restarts.
Cause: Unstable voltage, loose connections.
Symptom: LED not lit.
Display Anomalies: Black screen/distorted display/low contrast.
Storage Errors: Unable to access Alibi/SD card read/write failures.
Cause: Loose card/full capacity, software bugs.
Keyboard Malfunctions: Unresponsive keys.
Cause: Dirt/damage.
Fault Resolution Steps
1. Preliminary Checks
Confirm power supply: Ensure 100-240VAC stability. Use a multimeter to measure L/N/GND (Section 5.4.1).
Grounding test: Ensure proper grounding with resistance <1Ω.
Restart: Power off for 5 minutes, then power on again.
2. Power Voltage Check (5.4.2)
Use a multimeter to measure the mainboard voltages: +5V, +12V, -12V should be stable. Replace the power module if anomalies are detected.
3. RS-232 Test (5.4.3)
Power off, connect the red probe to the transmit end and the black probe to the ground. Expect -5V to -15V in command mode; ±5V jumping in continuous mode. ±5V during printing. Replace the serial port board if anomalies are detected.
4. Internal Diagnostics
Navigate to maintenance → calibration tests: zero/range/linearity. Report “command failed–dynamic” during dynamic testing.
Set SW1-2 ON (SW1-4 as needed), power on to confirm. Clears parameters/calibration (EEPROM retained if OFF). Back up SD card data.
6. Advanced Troubleshooting
Software upgrade: Download firmware and install after master reset.
Sensors: For analog sensors, check mV output; for digital sensors, measure CAN voltage (Figure 4-131).
MT Security: Unlock using the Insite tool (Sections 5.5.6.7).
Prevention: Regular calibration, avoid overloading/moisture. Record fault time/symptoms and contact the service department. Common resolution rate >90%, professional repair <5%.
Conclusion
The Toledo ND245 Electronic Weighing Instrument stands as a reliable partner in the vehicle scale field, thanks to its precise principles, rich features, and rigorous specifications. Through proper installation, daily operation, and parameter optimization, users can achieve efficient weighing. Regular maintenance and troubleshooting ensure long-term performance. This guide, approximately 4500 words in length, aims to simplify the application of the manual and recommends combining it with practical testing. For further in-depth information, refer to the original manual or seek professional support. The IND245 empowers your weighing journey, ensuring precision at every step!
Polarimetry is an important analytical technique widely applied in pharmaceuticals, food, chemistry, sugar production, and research laboratories. Substances that can rotate the plane of polarized light are called optically active. By measuring this rotation, information such as concentration, purity, or specific rotation of the sample can be obtained.
The WZZ-3 Automatic Polarimeter, manufactured by Shanghai Shenguang Instrument Co., Ltd., is a modern optical instrument that adopts the photoelectric automatic balance principle. Compared with manual polarimeters, it eliminates human reading errors, improves accuracy, and allows direct digital display of results. The instrument is equipped with multiple measurement modes, temperature control functions, and digital data interfaces, making it suitable for high-precision laboratory analysis.
This guide aims to provide a comprehensive reference for users by covering:
Principle and features of the WZZ-3 polarimeter
Temperature control methods
Calibration and adjustment procedures
Operation and routine maintenance
Common faults and troubleshooting methods
I. Principle and Main Features
1.1 Working Principle
The WZZ-3 polarimeter works based on the photoelectric automatic balance method. The measurement process can be summarized in the following steps:
Light Source
The WZZ-3 typically uses a high-stability LED combined with an interference filter to provide a monochromatic beam close to the sodium D line (589.44 nm).
Some older models use a sodium lamp.
Polarization System
The monochromatic light passes through a polarizer, producing linearly polarized light.
When the polarized light passes through an optically active substance (such as sugar solution, amino acid, or pharmaceutical compound), its polarization plane is rotated by a certain angle.
Analyzer and Detection
At the analyzer end, a photoelectric detector receives the rotated polarized light.
The change in light intensity is converted into an electrical signal.
Automatic Balance
The microprocessor adjusts the analyzer position automatically until light intensity reaches balance.
The rotation angle is calculated and displayed digitally as optical rotation, specific rotation, concentration, or sugar content.
1.2 Main Features
Multi-function Measurement: Supports direct measurement of optical rotation, specific rotation, concentration, and sugar content.
High Precision: Resolution up to 0.001°; repeatability ≤ 0.002°.
Automatic Operation: Automatically performs multiple measurements and calculates average values.
Temperature Control: Built-in temperature control ensures stable measurement conditions.
Digital Display and Output: Large LCD screen for real-time display; RS-232/USB interface for data transfer.
User-friendly: Simplified operation, reduced manual intervention, and minimized reading errors.
II. Temperature Control System
Optical rotation is temperature-dependent. Even small temperature changes can lead to measurable variations. The WZZ-3 is equipped with temperature control functions to ensure reliable and repeatable measurements.
2.1 Temperature Control Components
Sample Compartment with Jacket: Allows connection to a circulating water bath for precise control.
Built-in Heating Unit: Some models include an electric heater and sensor for direct temperature regulation.
Temperature Sensor: Monitors real-time sample temperature and provides feedback to the control system.
2.2 Control Range and Accuracy
Control Range: 15 ℃ – 30 ℃
Accuracy: ±0.5 ℃
2.3 Usage Notes
Preheat the instrument until both the light source and the temperature control system stabilize.
Ensure stable water circulation when using an external water bath.
For high-precision tests, always use a thermostatic water bath together with temperature-controlled sample tubes.
After use, drain water lines promptly to prevent scale buildup.
III. Calibration and Adjustment
3.1 Zero Adjustment
Turn on the instrument and allow 15–20 minutes for preheating.
Insert an empty sample tube (or keep the cell empty).
Select the Optical Rotation Mode and press the zero key to set the reading to 0.000°.
3.2 Calibration with Standard Sample
Use the supplied quartz calibration plate or standard solution.
Place it in the sample compartment and measure.
Compare measured value with certified standard value:
If deviation ≤ ±0.01°, calibration is valid.
If deviation exceeds the tolerance, enter the calibration interface, input the standard value, and let the system adjust automatically.
3.3 Instrument Adjustment
Verify that the light source is stable and sufficient in intensity.
Ensure optical alignment so that the beam passes centrally.
Re-measure the standard sample repeatedly to confirm consistency.
IV. Operation and Routine Maintenance
4.1 Operating Steps
Sample Preparation
Ensure the solution is homogeneous, transparent, and free of air bubbles or suspended particles.
Power On and Preheating
Start the instrument and allow adequate preheating time for light and temperature stabilization.
Mode Selection
Choose among optical rotation, specific rotation, concentration, or sugar content according to experimental requirements.
Loading the Sample Tube
Fill the tube without air bubbles; seal the ends properly.
Measurement
Press the measurement key; the instrument automatically performs multiple readings and calculates the average.
Reading and Output
View results on the LCD; if necessary, export data through the interface to a computer or printer.
4.2 Routine Maintenance
Sample Compartment Cleaning: Clean regularly to prevent contamination.
Optical Components: Do not touch with bare hands; clean with ethanol and lint-free cloth if necessary.
Light Source: Inspect periodically; replace if intensity decreases significantly.
Environmental Requirements: Keep away from direct sunlight, vibration, and high humidity.
Long-term Storage: Switch off power, disconnect cables, and cover with a dust-proof cover.
V. Common Faults and Troubleshooting
5.1 Light Source Not Working
Possible Causes: Lamp/LED damaged, power supply fault, or loose connection.
Possible Causes: Sample turbidity, temperature fluctuation, insufficient preheating.
Solution: Use a filtered and homogeneous sample; extend preheating; apply thermostatic bath.
5.3 Large Measurement Deviation
Possible Causes: Not calibrated, expired standard sample, or improper zero adjustment.
Solution: Re-zero the instrument; calibrate with quartz plate; replace standards.
5.4 Communication Failure
Possible Causes: Interface damage, incorrect baud rate, faulty cable.
Solution: Verify port configuration; replace cable; check PC interface.
5.5 Temperature Control Failure
Possible Causes: Faulty temperature sensor, unstable water circulation.
Solution: Inspect circulation system; check sensor connection; replace if necessary.
VI. Conclusion
The WZZ-3 Automatic Polarimeter is a high-precision, multi-functional instrument widely used for analyzing optically active substances. Its strengths lie in:
Photoelectric automatic balance technology
Accurate temperature control
Multi-mode measurement capability
Digital display and data communication
To ensure reliable results, users should pay special attention to:
Calibration procedures (zero adjustment and standard sample calibration)
Temperature stability (always use thermostatic control for critical experiments)
Sample preparation (avoid bubbles and impurities)
Routine maintenance (cleaning, light source inspection, and storage conditions)
By following the outlined procedures and troubleshooting methods, users can maintain the instrument’s accuracy, extend its lifespan, and ensure consistent performance in laboratory applications.
The 752N Plus UV-Vis spectrophotometer displays a “low energy” warning (which may be accompanied by an NG9 or other low-energy prompt) at a wavelength of 220 nm (in the UV region), regardless of whether there is liquid in the cuvette or not. However, it functions normally at wavelengths above 300 nm (in the visible region). This is a typical fault related to the UV light source. Based on the instrument’s principles and common cases, the following provides a detailed explanation of the causes, diagnostic steps, and solutions. This issue does not affect visible light measurements, but if ignored for a long time, it may lead to data deviations in the UV region, affecting the accuracy of UV absorption analyses of nucleic acids and proteins.
Analysis of Fault Causes
The 752N Plus spectrophotometer employs a dual-light source design: a deuterium lamp (Deuterium lamp) is responsible for the UV region (approximately 190 – 400 nm, providing a continuous UV spectrum), and a tungsten-halogen lamp (Tungsten-halogen lamp) is responsible for the visible region (approximately 320 – 1100 nm). The instrument automatically switches to the deuterium lamp at wavelengths below 325 nm to ensure sufficient energy at short wavelengths.
Primary Cause: Deuterium Lamp Aging or Energy Degradation
The lifespan of a deuterium lamp is typically 800 – 1000 hours. After 2 – 3 years of use, the evaporation of the tungsten filament or a decrease in gas pressure can lead to insufficient output energy in the short-wavelength band (such as 220 nm), triggering a “low energy” alarm. Your symptoms highly match this scenario: there is no difference between an empty cuvette and a cuvette with liquid (ruling out cuvette problems), and only the UV region is abnormal (the tungsten lamp is normal). In similar cases, this type of fault accounts for more than 70% of UV-related issues.
Secondary Causes
Optical Path Contamination or Misalignment: Dust in the sample chamber, oxidation of mirrors, or clogging of slits can preferentially absorb UV light (since UV wavelengths are short and prone to scattering). However, since the problem persists with an empty cuvette, this possibility is relatively low.
Insufficient Warm-up or Switching Fault: The instrument requires a warm-up time of 30 – 60 minutes to stabilize the light sources. If the UV/visible switching motor or circuit board is damaged, it may also result in a false “low energy” warning.
Electrical Problems: An unstable power supply (<220V ± 10%) or a decrease in the sensitivity of the detector (photomultiplier tube, PMT) could be factors, but since the instrument functions normally above 300 nm, the probability is low.
Environmental Factors: High humidity (>85%) or low temperature (<15°C) can accelerate lamp degradation.
Eliminating the Impossible: The problem is not related to the liquid in the cuvette (as it occurs with an empty cuvette as well), and it is not a wavelength calibration deviation (since other wavelengths are normal).
Diagnostic Steps
Follow the steps below in order for self-inspection. Ensure that the power is turned off before operation to avoid static electricity. Required tools: white paper, compressed air, a lint-free cloth, and a multimeter (optional).
Basic Verification (5 – 10 minutes)
Confirm Warm-up: After turning on the instrument, wait for at least 30 minutes (ideally 60 minutes) and observe the light source chamber (through the ventilation grille on the back cover). The deuterium lamp should emit a weak purple light (UV light is invisible, but the lamp should have a uniform brightness). If there is no purple light or it flickers, it indicates a lamp fault.
Test Multiple Wavelengths: Set the wavelengths to 220 nm (UV), 250 nm (UV edge), 350 nm (visible switching point), and 500 nm (visible). If only the first two wavelengths show low energy, it confirms a deuterium lamp problem.
Check Error Codes: If the screen displays “NG9” or “ENERGY ERROR”, it directly indicates that the deuterium lamp energy is below the threshold (usually <50%).
Optical Path Inspection (10 – 15 minutes)
Open the sample chamber cover and shine a flashlight (white light) inside: Observe whether the light beam passes straight through the cuvette position without scattering or dark spots. If there are any issues, clean the sample chamber (use compressed air to blow away dust and a soft cloth to wipe the mirrors and slits).
Empty Cuvette Test: Insert a matching quartz cuvette (UV-specific, with a 1 cm optical path), close the cover tightly, press [0%T] to zero the instrument, and then press [100%T] to set the full scale. If the transmittance (%T) at 220 nm is still less than 90%, the cuvette can be ruled out as the cause.
Dark Environment Test: Turn off the lights in the room, set the wavelength to 530 nm (with a wide slit), and place a piece of white paper in the sample chamber to observe the light spot. If there is no light or the light is weak, check the integrity of the optical path.
Power Supply Test: Use a multimeter to check that the 220V power supply is stable and properly grounded.
Switching Test: Manually switch the mode (if the instrument supports it) or check the system settings (avoid accidentally selecting the “energy mode” in the menu).
If an oscilloscope is available, measure the output of the PMT (it should normally be >0.5V at 220 nm).
Diagnostic Step
Operation Points
Expected Results
Abnormal Indications
Warm-up Verification
Turn on the instrument and wait for 30 – 60 minutes, then observe the lamp
The deuterium lamp emits a uniform purple light
No light or flickering → Lamp fault
Multiple Wavelength Test
Set the wavelengths to 220/250/350/500 nm
Transmittance >95%T at both UV and visible wavelengths
Low transmittance only at UV wavelengths → Deuterium lamp problem
Optical Path Inspection
Shine a flashlight inside and clean the sample chamber
The light beam is clear
Scattering or dark spots → Contamination
Error Code Check
Read the screen
No error codes
NG9 → Insufficient energy
Solutions
Immediate Optimization (No Parts Required, Success Rate: 30%)
Extend the warm-up time to 1 hour and recalibrate the zero and full scale.
Clean the optical path: Use a lint-free cloth and isopropyl alcohol to wipe the cuvette and sample chamber, avoiding scratches.
Optimize the environment: Maintain a room temperature of 20 – 25°C and a humidity level of less than 70%.
Software Reset: Press and hold the reset button to restore the factory settings.
Steps: a. Turn off the power and open the back cover of the light source chamber (unscrew the screws). b. Pull out the old deuterium lamp (model: D2 lamp, 12V/20W, ensure the specifications match the 752N Plus manual). c. Install the new lamp: Align it with the axis and gently push it into place to secure it (do not touch the bulb). d. Turn on the instrument again, let it warm up for 60 minutes, and then run the self-test (menu > diagnostics). e. Calibration: Use a standard filter (e.g., a 220 nm holmium glass filter) to verify the wavelength and energy.
Cost and Precautions: The price of a deuterium lamp is approximately 300 – 500 yuan (available on Taobao or instrument stores). After replacement, record the usage hours (the instrument has a timer). If the switching motor is suspected to be faulty (web:0), check the drive board (seek professional repair).
Verification: After replacement, the transmittance (%T) of an empty cuvette at 220 nm should be greater than 98%, and the absorbance (A) should be 0.000 ± 0.002.
Other Repairs
Optical Path Adjustment: If there is misalignment, fine-tune the slit screws (requires tools from the manufacturer).
Circuit Board Replacement: If the PMT or CPU board is faulty, replace them (cost: 800 – 1500 yuan).
Annual Maintenance: Calibrate the wavelength and energy annually to extend the instrument’s lifespan.
Preventive Recommendations
Daily Maintenance: Conduct an empty cuvette test for both UV and visible regions every week. Replace the deuterium lamp when the usage exceeds 700 hours as a precaution.
Proper Operation: Always warm up the instrument before use; use quartz cuvettes (glass absorbs UV light); avoid exposing the instrument to direct sunlight and high humidity.
Backup: Keep 1 – 2 spare deuterium lamps on hand to minimize downtime.
This type of fault is common in instruments that have been in use for 1 – 2 years. In most cases, replacing the deuterium lamp can quickly resolve the issue. If the instrument also starts to show abnormalities above 300 nm, it may indicate overall aging, and upgrading to a newer model is recommended.
