What are the measurement parameters of water quality detectors?

Water quality detectors generally refer to desktop testing instruments, equipped with corresponding digestion instruments, easy to operate, moderate in size, and widely used in emergency detection, industrial wastewater, domestic sewage, sewage treatment, medicine and chemical industry, electroplating, river metallurgy, scientific research, colleges and universities, and other fields.

It can detect cod, ammonia nitrogen, total phosphorus, total nitrogen, total chromium, copper, nickel, zinc, iron, turbidity, etc. One instrument can accommodate a variety of parameters, and the spectrophotometric method is used for measurement, and the general measurement error is 5%.

Taking cod as an example, the operation process is divided into several steps:

1. Perform zero calibration

2. Take 5ml of distilled water into the colorimetric tube

3. Take another 5ml water sample to another colorimetric tube

4. Add 0.5ml of concentrated sulfuric acid to the two colorimetric tubes respectively, then add 0.5% of permanganate index reagent, cover and shake well, place in a heated digestion apparatus, and heat for 13min. (cool in cold water).

5. Put the blank and sample into the instrument for zero-point calibration, and then put in the sample for testing, and the indicated value is the concentration.

Precautions:

Samples cannot be left for a period of time or repeated test comparisons at different time periods. The measured data should be within the corresponding range. If not, the water sample can only be roughly judged. If accurate data is required, a low range or a high range should be selected or diluted, so that the measured data is within the corresponding range.

The colorimetric solution should not be placed in the digestion tube for a long time, and the digestion tube and its experimental utensils should be cleaned in time. The water sample pretreatment process and the colorimetric process should be completed compactly. The solution after colorimetry should not be dumped at will but should be collected and processed centrally.