The principle of formaldehyde detector

        The formaldehyde detector collects air samples from the testing site. The formaldehyde in the air is absorbed by the phenol reagent solution and reacts to form azine. The azine is oxidized by the color developer ferric ion in the acidic solution to form a blue-green compound. According to the color depth, direct colorimetric determination is performed on site. Since the detection value of indoor pollution is closely related to the temperature, humidity, and air pressure of the testing environment, the detected value will often deviate from the expected value according to normal testing. The machine on the right side of the picture is a six-in-one detector. The six-in-one detector produced by Wuyanjie can quickly detect six kinds of indoor pollutants : formaldehyde, benzene, ammonia , toluene , xylene , and TVOC. It can display the date, test time, and the temperature and humidity data of the test site. The left side is a Chinese display LCD screen, the right side is a sampling timing operation, and the middle is a thermal printer. It can quickly sample and analyze on site in real time, and can print the test date, time, temperature, humidity, implementation standards, formaldehyde content, and whether it is qualified into a report. Formaldehyde detection adopts the national standard phenol reagent spectrophotometry method and uses imported photoelectric sensors with high detection accuracy and low detection limit, which solves the shortcomings of electrochemical formaldehyde detector sensors that the zero point is easy to drift and is easily interfered by other chemical gases during sampling.