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The principle and classification of COD measuring instrument

by:BOQU     2022-10-07

The COD analyzer is mainly divided into a display module, optical detection cell, supporting reagent group and electronic circuit chip control module, etc. Emergency detection configuration can be selected according to on-site working conditions. The display panel module can be divided into the data display area, selection key, up and down key, function key, zero calibration key, etc. The main components of the reagent group are potassium dichromate (potassium permanganate for drinking water), sulfuric acid, mercury sulfate, silver sulfate, and water.

Working principle:

COD refers to adding a known amount of potassium dichromate solution to the water sample, in a strong sulfuric acid medium, using silver sulfate as a catalyst, and after high-temperature digestion, the COD value is determined by spectrophotometry. That is, the absorbance of trivalent chromium produced by the reduction of potassium dichromate is measured at a wavelength of 620 nm; the COD value in the sample is proportional to the increase in absorbance of trivalent chromium so that the absorbance value can be converted into the COD value in the sample.

Features of COD measuring instrument:

1. Stable. Reliable

According to the Ministry of Environment HJ828—2017 and HJ/T399—In accordance with the requirements of the 2007 standard, the technology has launched this COD determination pre-filled tube reagent, in order to avoid the tedious operation of the user to prepare the reagent and the test process, improve the detection efficiency, and ensure the stability, accuracy and reliability of the detection.

2. Lifespan

It adopts imported mainstream optical components for R&D and production, the luminous body has a service life of up to 100,000 hours, and the instrument has a long warranty.

3. Portable

The portable COD rapid analyzer adopts an integrated design. The host, digester, etc., pipettes, reagents, colorimetric tubes, etc. are all packed in a portable suitcase, which is convenient for customers to detect on-site. Environmental engineering process transformation, etc.

4. Automatic correction

The analyzer performs calibration according to the calibration time and calibration type set by the user. If the obtained result exceeds the set limit, the original calibration parameters will not be replaced and an alarm signal will be output.

Common classification of COD water quality measuring instruments:

COD rapid detector

Basic composition: digestion reactor (6/16/25-hole digester). Cooling tank rack. Cuvette rack. Prefabricated COD reagent (optional powder). High-end pipette. Several integrated tubes for digestion and colorimetry. Portable printer. Printing paper. Power bank, etc. COD ammonia nitrogen analyzer

The COD ammonia nitrogen analyzer can be used to measure the concentration of two parameters of COD and ammonia nitrogen in water samples. The concentration range of COD is 0~15000mg/L, and the variation range of ammonia nitrogen concentration is 0~50mg/L. Chinese display the value of COD and ammonia nitrogen, the unit is mg/L.

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