Summary:

Formaldehyde is recognized by the World Health Organization as a carcinogen. Relevant statistics show, decorate the main culprit that is children leukaemia, this is because formaldehyde concentration inside the house is too high cause, the family of 90% leukaemia children is decorated inside half year. Therefore, it is necessary to monitor formaldehyde concentration, at this time it is necessary to use CH2O gas sensor, there are many kinds of it, the following JXCT briefly introduce the characteristics of two kinds of CH2O sensor:

Semiconductor CH2O gas sensor principle:

Many manufacturers use formaldehyde sensors based on semiconductor principles as sensors for formaldehyde detection. Formaldehyde adsorbed on the surface of metal oxide, the resistance of semiconductor gas sensor changes, and then the concentration of formaldehyde can be estimated according to the change of resistance. Formaldehyde conducts electricity differently from air. In theory, the amount of formaldehyde can be estimated from the current conductivity of the air.

But in practice, such measurements are almost impossible to obtain. First, the conductivity of formaldehyde is different, and second, the conductivity will vary with the humidity in the air. Not only will formaldehyde be measured, but when the external humidity changes, the semiconductor gas sensor will also react. Its disadvantages are poor selectivity, low accuracy, poor linearity, high power consumption, the advantage is low price, long service life.

Electrochemical CH2O gas sensor principle:

Electrochemical formaldehyde sensors have much less interference than semiconductor formaldehyde sensors. The electrochemical formaldehyde sensor filters out some other elements in the air, such as water, through a membrane. The formaldehyde then reacts with a chemical catalyst, causing voltage and current fluctuations. It has the advantages of low power consumption, high accuracy and good linearity, but the cost of the gas sensor is slightly higher than that of the semiconductor principle.

Finally, JXCT reminds you of two points for attention when choosing CH2O gas sensor:

(1) Choose the formaldehyde sensor with strong anti-interference ability. If the gas in the air interferes too much with other smells, the formaldehyde concentration test in the air is not accurate.

(2) If you can quickly monitor without calibration, you can choose formaldehyde sensor modules. Many models of modules have been calibrated by manufacturers, which can enable customers to quickly develop new products.

The CH2O sensor developed by JXCT has strong anti-interference ability, high sensitivity, high resolution, small size, easy installation, no need for secondary calibration, and support secondary development. The gas sensor module is widely used in the production and installation of portable and fixed gas detectors. And various gas detection occasions and equipment.