In acid solution, trivalent chromium is oxidized to hexavalent chromium by potassium permanganate. Under high temperature and high pressure, for potassium persulfate oxidation digestion solution and water samples, various nitrogen-containing compounds in the water samples are converted into nitrates through potassium persulfate oxidation digestion. Under acidic conditions, the nitrate complex reacts with the chromogenic agent, and finally the color is proportional to the nitrogen content in the sample according to color depth, so as to obtain the total nitrogen content in the 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.

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

1 Method basis: potassium permanganate oxidation spectrophotometry.

2 Measuring range: 0-20 mg/L (divided into 0-1mg/L; 0.2-5mg/L; 0.2-20mg/L).

3 Accuracy: no more than ±10% or no more than ±3% FS.

4 Repeatability: no more than ±5% or no more than ±2% FS.

5 Measurement period: The minimum measurement period is 25 minutes.

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

7 Calibration cycle: regular manual calibration, with no automatic calibration function.

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

9 Reagent consumption: less than 0.50 RMB/sample.

10 Output: 2 channels of RS-232; 1 channel of 4-20mA.

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

12 Power supply: AC230±10%V, 50±10%Hz, 5A.