Ammonia-Nitrogen Analyzer: Principles, Usage, Maintenance, and Brands Overview

I. Principles of Ammonia-Nitrogen Analyzer

The ammonia-nitrogen analyzer is an instrument specifically designed to detect ammonia-nitrogen content in water samples. It is widely used in environmental monitoring, drinking water treatment, and wastewater treatment. The analyzer’s working principle is mainly based on chemical reactions and optical measurements. Common measurement methods include the Nessler’s reagent spectrophotometric method and the salicylic acid spectrophotometric method. Taking the Nessler’s reagent method as an example, the principle is that free ammonia or ammonium ions in the water sample react with Nessler’s reagent (an alkaline solution of potassium iodide and mercuric iodide) to form a pale reddish-brown complex. The absorbance of this complex is proportional to the ammonia-nitrogen content. By measuring the absorbance at a specific wavelength (such as 420 nm), the ammonia-nitrogen concentration in the water sample can be calculated.

II. Usage Instructions

Preparation:

• Clean the cuvettes and measuring cups to ensure no residues or impurities.
• Connect the instrument to a power source, turn it on, and preheat for at least half an hour.
• Set detection parameters such as detection range and sample volume according to the instrument manual.

Sample Processing:

• Take a certain amount of water sample (usually 10 mL), add appropriate reagents (such as N-NH3-1 and N-NH3-2 reagents), shake well, and let stand for a certain time (such as 10 minutes).
• If the water sample contains interfering substances such as suspended solids, residual chlorine, calcium, and magnesium ions, appropriate pretreatment is required to eliminate the interference.

Measurement:

• Add the processed water sample to the cuvette, place it in the instrument’s measurement seat, and cover with a light-shielding cover.
• Start the instrument for measurement and wait for a certain time (usually a few minutes to tens of minutes) until the display stabilizes.
• Read and record the ammonia-nitrogen concentration value.

Cleaning and Maintenance:

• After measurement, clean the cuvettes and reagent bottles, and store them properly.
• Regularly calibrate and maintain the instrument to ensure stable performance.

III. Common Faults and Repair Methods

• Instrument Startup Abnormality: Causes include power failure, internal circuit failure, or software failure. Repair methods include checking the power supply, replacing damaged power sources, inspecting internal circuits, repairing faulty circuits, and attempting to restart the instrument or update the software.
• Deviation in Measurement Results: Causes include reagent issues, instrument calibration problems, or improper operation. Repair methods include checking if the reagents are expired or contaminated, replacing them with new ones, performing instrument calibration, and ensuring accurate and reliable operation, as well as checking the correctness of the operation process and correcting improper operations.
• Communication Failure: Causes include faulty communication cables, loose interfaces, or software compatibility issues. Repair methods include checking the integrity of communication cables, replacing damaged ones, inspecting interface connections, reconnecting them, and checking software compatibility, updating the software, or replacing it with more compatible software.
• Mechanical Failure: Causes include worn pump bodies and loose pipelines. Repair methods include inspecting the wear condition of mechanical parts, replacing severely worn components, checking pipeline connections, and re-securing them, as well as performing regular instrument maintenance.
• Display Panel Abnormality: Causes include a damaged display screen, poor line contact, or power failure. Repair methods include checking if the display screen is damaged and replacing it, inspecting line connections and reconnecting them, and checking the power supply and replacing damaged power sources.

IV. Summary of Brands and Models Repaired by Rongji Electromechanical Company

• Hach:
  • NA8000
  • DR3900: Benchtop Spectrophotometer supporting ammonia-nitrogen determination
  • DR6000: High-precision Benchtop UV-Vis Spectrophotometer supporting ammonia-nitrogen determination
  • Nitratax plus sc: Online Ammonia-Nitrogen Analyzer
  • HQD Series, HQ40D, HQ30D
• YSI (Xylem Inc.):
  • ProDSS: Multi-parameter Water Quality Analyzer with ammonia-nitrogen determination module
  • IQ Sensor Net Series: AmmoLyt Plus: Online Ammonia-Nitrogen Sensor, VARiON Plus: Online Multi-parameter Ion-selective Electrode System
• Thermo Fisher Scientific:
  • Orion Star A Series: Star A329: Benchtop Multi-parameter Analyzer supporting ammonia-nitrogen determination, Star A326: Portable Multi-parameter Analyzer supporting ammonia-nitrogen determination
  • Orion AQUAfast AQ4000: Multi-parameter Photometer supporting ammonia-nitrogen determination
• Hanna Instruments:
  • HI83399: Multi-parameter Photometer supporting ammonia-nitrogen determination
  • HI96715: Portable Ammonia-Nitrogen Photometer
  • HI93532: Benchtop Ammonia-Nitrogen Analyzer
• Horiba:
  • LAQUAtwin NH4-11: Portable Ammonia-Nitrogen Analyzer
• Lovibond:
  • MD 600: Multi-parameter Portable Water Quality Analyzer supporting ammonia-nitrogen determination
  • SpectroDirect: Spectrophotometer supporting ammonia-nitrogen determination
• LaMotte:
  • Smart 3 Colorimeter: Portable Multi-parameter Water Quality Analyzer supporting ammonia-nitrogen determination
  • Nitrate Test Kit: Ammonia-Nitrogen Test Kit
• Palintest:
  • Photometer 7500: Benchtop Multi-parameter Analyzer supporting ammonia-nitrogen determination
  • AquaPal Series: AquaPal Photometer: Portable Multi-parameter Water Quality Analyzer supporting ammonia-nitrogen determination, Macro 900 Series: Multi-parameter Portable Water Quality Analyzer supporting ammonia-nitrogen determination
• Mettler Toledo:
  • SevenExcellence Series: S470: Benchtop Multi-parameter Analyzer supporting ammonia-nitrogen determination, S475: Benchtop Multi-parameter Analyzer supporting ammonia-nitrogen determination
• Aquaread:
  • AP Series: AP-7000: Multi-parameter Water Quality Probe supporting ammonia-nitrogen determination, AP-8000: Multi-parameter Water Quality Probe supporting ammonia-nitrogen determination
• Shimadzu:
  • UV-Vis Spectrophotometer Series: UV-1900i: UV-Vis Spectrophotometer supporting multiple water quality parameters determination, including ammonia-nitrogen, UV-2600i: UV-Vis Spectrophotometer suitable for high-precision water quality analysis, including ammonia-nitrogen, UV-3600i Plus: High-performance UV-Vis Spectrophotometer suitable for ammonia-nitrogen determination in complex water samples
  • TOC-L Analyzer Series: TOC-LCPH/CPN: Total Organic Carbon Analyzer, which can be used for ammonia-nitrogen determination with appropriate accessories, TOC-LCSH/CSN: High-sensitivity Total Organic Carbon Analyzer supporting ammonia-nitrogen determination
  • Ion Chromatography Series: ICPE-9800 Series: Inductively Coupled Plasma Emission Spectrometer suitable for trace ammonia-nitrogen determination, ICPE-9000 Series: Multi-function Ion Chromatograph that can be used for ammonia-nitrogen determination
  • Automatic Analyzer Series: AA-7000 Series: Atomic Absorption Spectrometer, which can be used for ammonia-nitrogen determination with appropriate accessories
  • Nexis GC-2030 Gas Chromatograph: Can be used for ammonia-nitrogen determination with appropriate detectors and columns.

Rongji Electromechanical Company has nearly 30 years of experience in repairing ammonia-oxygen analyzers and can quickly repair various instruments. Additionally, the company回收 (recycles) and sells various used ammonia-oxygen analyzers. For more information, please contact us.