PH3 gas sensor applied to granary insecticide

The macro-control of food is the main means of safeguarding national food security, and the grain storage is the basis for macroeconomic regulation and control. Therefore, the intelligent control and precise management of the grain storage is the key to safe and efficient grain storage.

The most important food storage is de-worm treatment. Aluminum phosphide is a very effective storage insecticide for the food sector in China. It is widely used in granary storage. When it is exposed to water or moisture, it can deliquesce and release toxic phosphine gas.

The grain depot laboratory technicians will be exposed to phosphine gas during sampling and testing, and the custodian will check the temperature, humidity, and check the grain condition and insect condition. Some of them will cause phosphine poisoning due to lack of safety and health knowledge.

In order to investigate the concentration of phosphine in the granary during fumigation and the time to fall below the national sanitary standard after fumigation, it is necessary to monitor the concentration of phosphine gas in the warehouse after fumigation and the environmental concentration of O2 and CO2 to provide protection for the health of the personnel. Scientific basis.

The granary is connected with an arched warehouse, with a storage capacity of 600,000 kg, two windows with six doors, no detoxification device, and a double-layered thermal insulation structure. The warehouse is stored in the summer and the new wheat is stored in the warehouse. The wheat pile is 4m high. Fumigation was carried out by a conventional method, and an aluminum phosphide of 8.3 g/m3 was placed around the wheat heap. After the application, the warehouse was fumigation for one week, and then the doors and windows were opened for ventilation for 4 days and then closed again. The concentration of phosphine in the silo and grain piles during the above-mentioned various periods after fumigation was monitored for 1 d before fumigation.

During fumigation, the concentration of phosphine in the silo and grain piles was very high, peaked at 48h in the warehouse, peaked at 96h in the grain pile, and was higher in the phosphine concentration chamber than in the grain pile in the first two days. many. However, as time goes by, the difference between the two becomes smaller and tends to be balanced. It shows that the phosphine produced after the deliquescent of aluminum phosphide quickly spreads in the warehouse and gradually diffuses into the grain pile. After two days of gas, the concentration of phosphine in the warehouse fell to the national health standard.

After the second closed position, the concentration of phosphine in the grain pile gradually decreased, while the inside of the warehouse first rises and then falls, indicating that the phosphine in the grain pile is gradually released into the warehouse space after the second closed position, causing the concentration in the warehouse to rise. . It was not until the 9th day that the phosphine concentration in the grain piles and silos fell below the national health standard. It is safer to enter the warehouse after about half a month from the start of the venting after the fumigation.

In order to further improve the safety of the granary staff, a PH3 gas sensor is added to the granary to monitor the concentration of PH3 in real time until the PH3 gas concentration reaches below the national sanitary standard.

Shenzhen Gongcai Network Technology Co., Ltd. provides PH3 gas sensor, as follows:

PH3 gas sensor PH3-A1:

Principle of electrochemistry

4 series size

The range is 0~10ppm

Linear output

Can resist interference from H2, NH3, CO2

PH3 gas sensor PH3-B1:

Principle of electrochemistry

7 series size

The range is 0~10ppm

Linear output

Can resist interference from H2, NH3, CO2

Large range PH3 gas sensor PH3-BE:

Principle of electrochemistry

7 series size

The range is 0~2000ppm

Linear output

Can resist interference from H2, NH3, CO2