It is a new generation of full-automatic COD online monitor based on China's national standard method-determination of chemical oxygen demand, dichromate method. Redox reaction occurs in the mixed solution formed by water samples, potassium dichromate, silver sulfate (as a catalyst to oxidize linear aliphatic compounds more fully) and concentrated sulfuric acid under high temperature and high-pressure environment, during which the Cr (VI) in the solution is reduced to Cr (III), so that the color of the mixed solution changes. The degree of color change of the solution corresponds to the chemical oxygen demand (COD) of the water sample, and the instrument can directly determine the COD value of the water sample through the optical signal. The chloride ion in water sample is the main interfering substance. The interference of chloride can be eliminated by adding mercury content to complex the chloride ion in water sample.

Characteristics:

l Valve components selection. It can select the reagent sampling sequence, with flexible channels, variable functions, minimum dead volume, easy maintenance, long service life and other advantages.

l Printing function. It can be connected to a printer (optional order) to print the measured data in time.

l It adopts 7-inch touch screen, with simple operation interface, easy for users to learn, operate, and maintain.

l Super large data storage capacity. It can realize storage of historical data for no less than 5 years (measurement interval is 1 time/1h), which greatly meets the needs of customers.

l Automatic leakage alarm function. When reagent leakage occurs, the instrument will automatically alarm to remind the user to perform maintenance.

l Light signal recognition function to ensure high accuracy of quantification.

l Simple and convenient chemical reagents maintenance. The reagents can be replaced once a month, which greatly reduces the maintenance of the user. It can realize accurate measurement of COD of 35000mg/L chloride ion.

l U disk one-click upgrade. The software update is much easier.

1 Method basis: Determination of the chemical oxygen demand-Dichromate method.

2 Measuring range: 10-5000 mg/L COD.

3 Accuracy: when ≥100mg/L, no more than ±10%; when ＜100mg/L, no more than ±8mg/L.

4 Repeatability: when ≥100mg/L, no more than ±10%; when <100mg/L, no more than ±6mg/L.

5 Measurement period: The minimum measurement period is 20 minutes. According to the actual water sample, the digestion time can be arbitrarily modified within 5 to 120 minutes.

6 Sampling cycle: time interval (10～9999min arbitrarily adjustable) and hourly measurement mode.

7 Calibration cycle: adjustable at any interval any time from 1 to 99 days.

8 Maintenance cycle: generally, once a month, about 30 minutes each time.

9 Reagent consumption: less than 0.4 RMB/sample.

10 Output: RS-232, 4-20mA (optional).

11 Environment requirements: indoor with adjustable temperature, recommended temperature +5～28℃; humidity ≤90% (no condensation).

12 Power supply: AC220±10% V, 50±10% Hz, 5A.