Comprehensive Guide to Moisture Analyzers: Principles, Usage, Faults, and Repair

Moisture Analyzer Overview

A moisture analyzer, also known as a moisture meter or a moisture detector, is a device used for the rapid and accurate determination of water content in substances. It finds extensive application in various industries such as pharmaceuticals, plastics, metallurgy, mining, coal, building materials, chemicals, food, grain, feed, seeds, tea, agriculture and forestry, papermaking, rubber, and textiles. With diverse working principles and usage methods, moisture analyzers may encounter various faults during operation, necessitating corresponding repair techniques.

Principles

The working principles of moisture analyzers are broadly classified into physical measurement methods and chemical measurement methods:

Physical Measurement Methods:

• Weight Loss Method: This involves heating the sample to evaporate the moisture and calculating the water content based on the weight difference before and after heating. Examples include infrared moisture analyzers and microwave moisture analyzers, which use far-infrared or microwave radiation to heat the sample and accelerate moisture evaporation.
• Distillation Stratification Method: This method separates water based on the boiling point differences of different substances and measures its volume or weight.
• Gas Chromatography Analysis: This technique uses gas chromatography to separate and detect the water content in the sample.

Chemical Measurement Methods:

• Karl Fischer Method: This is an internationally recognized standard method for measuring trace moisture. It involves the participation of water in the sample in an oxidation-reduction reaction with iodine and sulfur dioxide, generating pyridine hydroiodic acid and pyridine methyl sulfate. The consumed iodine is produced through electrolysis, and the reaction continues until the water is depleted. This method includes both volumetric and coulometric (electric) forms.

Usage Methods

The general usage steps for a moisture analyzer include:

1. Installation and Calibration:
   • Install components such as windshields, triangular brackets, and tray brackets.
   • Calibrate the instrument using weights to ensure accurate measurements.
2. Parameter Setting:
   • Set parameters such as temperature, drying method (e.g., microwave, infrared), and drying time as needed.
3. Measurement Steps:
   • Place the sample on the sample tray, ensuring uniform distribution.
   • Start the instrument to begin the heating and measurement process.
   • Wait for the measurement to complete and record the data.

Common Faults and Repair Methods

• Instrument Not Powering On:
  • Causes: Unstable voltage, blown fuse, improperly plugged-in cord.
  • Repair Methods: Check the power cord and plug, replace the fuse, ensure stable voltage.
• Light Not Turning On:
  • Causes: Test button not pressed, excessive sample weight, loose heater, broken filament.
  • Repair Methods: Press the test button, adjust the sample weight, check and secure the heater, replace the filament.
• Unstable Weighing:
  • Causes: Environmental influences (e.g., airflow), improperly placed sample tray, loose protective screws.
  • Repair Methods: Improve the measurement environment, reposition the sample tray, tighten the protective screws.
• Large Measurement Error:
  • Causes: Low voltage, poor operating environment, uneven sample, instrument aging.
  • Repair Methods: Ensure stable voltage, improve the operating environment, take uniform samples, calibrate the instrument regularly.
• Electrolysis Open Circuit or Short Circuit:
  • Causes: Poor plug contact, open or short-circuited electrode leads, electrode leakage.
  • Repair Methods: Check the plug and socket contact, replace open or short-circuited electrode leads, address electrode leakage.
• Damaged or Contaminated Probe:
  • Causes: Physical impact, corrosion, improper cleaning.
  • Repair Methods: Replace the damaged probe, plan cleaning times reasonably, adopt correct cleaning methods.
• Software Fault:
  • Causes: Software errors, no response.
  • Repair Methods: Reinstall the software or contact maintenance personnel for assistance.

Brands and Models of Moisture Analyzers Repaired by Longi Electromechanical

1. Mettler Toledo:
   • HX204: High-precision moisture analyzer
   • HS153: Halogen moisture analyzer
   • HE53: Economy moisture analyzer
   • HC103: General-purpose moisture analyzer
2. Sartorius:
   • MA160: High-precision moisture analyzer
   • MA100: Halogen moisture analyzer
   • MA35: Basic moisture analyzer
   • MA37: Halogen moisture analyzer
3. AND Instruments:
   • MX-50: Precision moisture analyzer
   • MF-50: Standard moisture analyzer
   • MS-70: Ultra-high precision moisture analyzer
4. KERN:
   • DAB Series: DAB 100-3, DAB 200-2
   • DLB Series: DLB 160-3
5. Shimadzu:
   • MOC-120H: Halogen moisture analyzer
   • MOC-63u: High-precision moisture analyzer
6. Ohaus:
   • MB Series: MB120, MB90, MB45
7. A&D:
   • HR-50: High-precision moisture analyzer
   • ML-50: Halogen moisture analyzer
8. Precisa:
   • EM 120-HR: Halogen moisture analyzer
   • EM 120: Basic moisture analyzer
9. RADWAG:
   • MA Series: MA 3Y, MA X2, MA R, MA 50.3Y
10. Kett:
    • FD Series: FD-720, FD-610
11. Denver Instrument:
    • IR Series: IR-35, IR-60
12. Michell Instruments:
    • S8000 Series: S8000 Remote, S8000 RS
13. CSC Scientific:
    • 100 Series: 100-0, 100-1
14. Brookfield:
    • PFT: Laboratory moisture analyzer
15. Thermo Fisher Scientific:
    • LDS Series: LDS 7000, LDS 7200
16. KYOTO ELECTRONICS (Kyoto Denshi):
    • AT-710
    • MKH-700
      • Type: Volumetric/Coulometric Karl Fischer Moisture Meter
      • Features: Wide measurement range for water content (0μg to 500mg H2O), high measurement accuracy (0.3%), and fine measurement resolution (0.1μg)
    • ADP-611 Automatic Karl Fischer Sample Heating Processor
      • Used in conjunction with the Karl Fischer moisture meter for automatic sample heating to vaporize the water in the sample.
      • Features: Complies with ISO 15512 and ASTM D6869 furnace test requirements, with automatic heating, automatic scanning of sample evaporation temperature, and heated conduit from the furnace to the moisture meter to prevent condensation.
      • Technical Parameters: Temperature control range of 50 to 300°C, sample boat capacity of 16mL, gas flow rate of 70 to 300mL/min, etc.
    • Other Models:
      • MKV-710D: Volumetric titration moisture meter, Karl Fischer moisture meter.
      • MKC-710D: Coulometric moisture meter, Karl Fischer moisture meter.
      • MKH-710M: Mixed method Karl Fischer moisture meter.
      • MKC-710B: Practical coulometric Karl Fischer moisture meter, Karl Fischer micro-water meter.
      • MKC-710S: Luxury Karl Fischer coulometric moisture meter.
      • MKC-710M: Flagship coulometric Karl Fischer moisture meter.

Longi Electromechanical Company has nearly 30 years of experience in repairing moisture analyzers and can quickly repair various types of instruments. Additionally, we offer recycling and sales services for various moisture analyzers. Welcome to consult us.