product name :PCM300-CODcr Chrome COD Online Analyzer

Principle of Measurement:

Under certain conditions, the water sample is added with a mixture of potassium dichromate and sulfuric acid to react in the digestion pool so that the organic reduced product in the sample is oxidized. Cr6+ is reduced to Cr3+ in the reaction, causing the color of the mixed solution to change. The colorimeter measures the change of the color of the mixed sample to calculate the consumption of potassium dichromate, which is eventually converted into the oxygen content required for the redox reaction, then the result is the chemical oxygen demand of the tested water sample.

Main Features:

●  When power failure occurs, the data will not be lost for it will be saved automatically;

●  It has fault alarm and over-limit alarm function, and it also has automatic fault diagnosis function;

●  It has automatic cleaning and automatic calibration function;

●  It has over-heat protection function: If the heating temperature is too high, the heater will automatically power off;

●  It has data storage and download functions;

●  With 7-inch touchscreen and simple operation interface, it is very convenient for users to learn, easy operate and maintain.

Typical Application:

CODcr on-line monitoring of municipal sewage import and export, pollution source discharge, and industrial wastewater export.





No more than ±10%



No more than ±10%




7-inch display, operation interface

Sampling Period


60~9999min adjustable mode, integral point measuring mode, external trigger mode

Calibration Cycle

Under the automatic calibration mode, ( ranging from 1 day to 99 days) it is adjustable in any interval or at any time.

Maintenance Interval

Normally once per month, about 30min per time

Power Supply



 4~20mA output


MODBUS  RS-232、RS-485


4-channel relay

Environmental Condition

Temperature-adjustable indoor, recommended temperature +5 ~ 40 °C

Humidity ≤85% (non-condensing)