The buffer solution needs to be stored at low temperature and protected from light, and the pH should be controlled within 9.6 ~11.5, otherwise the absorbance will be slightly higher. When the water sample contains volatile acids, it will reduce the pH of the distillate. It shall add ammonia to the distillate to make it neutral and then add the buffer. Otherwise, when pH＜9.8, some aniline compounds can develop color with the developer and interfere with the determination of phenol. The color reagent is very important to the accuracy of the experiment. Even the national standard mentions the purification of the reagent, so the selection of reagent is critically important for the experiment. According to experimental experience, each reagent added during the color development process must be fully mixed. The control of the color development time is essentially the control of the color development environment, to control water sample is consistent with the standard curve environment, so as to obtain accurate results.

The buffer solution needs to be stored at low temperature and protected from light, and the pH should be controlled within 9.6 ~11.5, otherwise the absorbance will be slightly higher. When the water sample contains volatile acids, it will reduce the pH of the distillate. It shall add ammonia to the distillate to make it neutral and then add the buffer. Otherwise, when pH＜9.8, some aniline compounds can develop color with the developer and interfere with the determination of phenol. The color reagent is very important to the accuracy of the experiment. Even the national standard mentions the purification of the reagent, so the selection of reagent is critically important for the experiment. According to experimental experience, each reagent added during the color development process must be fully mixed. The control of the color development time is essentially the control of the color development environment, to control water sample is consistent with the standard curve environment, so as to obtain accurate results.

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: spectrophotometry.

2 Measuring range: 0-10 mg/L.

3 Accuracy: no more than ±10%.

4 Repeatability: no more than ±10%.

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, each time is about 30 minutes.

9 Reagent consumption: less than 0.35 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.

13 Others: abnormal alarm and power failure will not cause data loss; touch screen display and command input; after abnormal reset and power on after power failure, the instrument will automatically discharge the residual reactants in the instrument and restores to working state.