Formaldehyde detecting device and formaldehyde detecting method

Abstract

The invention relates to a formaldehyde detecting device and method. The device comprises a first sensor, a second sensor, a temperature and humidity sensor and a controller. The method comprises thesteps that a first concentration signal C1 output by the first sensor and a second concentration signal C2 output by the second sensor are subjected to temperature compensation and / or humidity compensation according to a detecting signal output by the temperature and humidity sensor, and a formaldehyde concentration value is obtained according to the compensated first concentration signal C1t, thecompensated second concentration signal C2t and a third concentration signal C3t output by an algorithm and stored in the controller. The formaldehyde detecting device disclosed by the invention canidentify the disturbance gas under different to-be-detected environments, overcomes the technical defect of inaccurate detection data caused by the disturbance gas, and can eliminate the influence ofthe temperature and the humidity on formaldehyde detection simultaneously, and a solution scheme with excellent anti-disturbance property and high precision is provided for large-scale application ofthe formaldehyde detecting device to the fields of air purifiers, heating ventilation air conditioners and the like.

Description

technical field [0001] The invention relates to the field of air quality detection, in particular to a formaldehyde detection device and method. Background technique [0002] Formaldehyde is an important industrial raw material that widely exists in daily life. Formaldehyde has great harm to the human body. Due to its strong irritant, excessive inhalation can cause tears, runny nose, cough and other symptoms. Long-term exposure to formaldehyde exceeds the standard Formaldehyde can also react with ionic chlorides in the air to generate carcinogens, which have been listed as suspected carcinogens by the International Agency for Research on Cancer. With the improvement of living standards, the environmental decoration industry has developed rapidly, and the formaldehyde pollution caused by inferior decoration materials has become increasingly serious, and malignant cases caused by excessive formaldehyde have occurred from time to time. It is increasingly necessary to limit the ...

AI Technical Summary

Problems solved by technology

This scheme can identify the sudden increase of interfering gas in the measured environment, and eliminate the impact of the sudden increase of interfering gas on formaldehyde detection. The defect is that when the interfering gas already exists in the measured environment, the interfering gas cannot be identified, so the background cannot be eliminated The influence of interfering gases that already exist in the environment on the detection results; and this scheme does not eliminate the influence of temperature and humidity in the environment on the detection results, and the anti-interference performance is limited

In order to further improve the anti-interference performance of the sensor, patent documents CN104614423B and CN107655947A disclose a formaldehyde detection device, which uses two formaldehyde sensors of the same type to perform differential dynamic compensation to eliminate the influence of temperature and humidity on formaldehyde detection. The sensors are completely exposed to the actual detection environment. One is used as a measuring sensor and the other is used as a comparison sensor. The air intake channel of the comparison sensor is isolated by a semi-permeable membrane that can filter formaldehyde, so that it is only affected by the ambient temperature and humidity. Not affected by the formaldehyde gas concentration in the environment, the formaldehyde gas concentration signal in the actual environment can be obtained by making a difference between the output signals of the two sensors. This method can reduce the impact of the interference factors in the environment on the detection accuracy, but the cost of using two formaldehyde sensors is high , which is not conducive to large-scale application in the fields of air purifiers, HVAC, etc.

In summary, there is no high-precision and low-cost formaldehyde sensor in the prior art that can completely eliminate the interference caused by interfering gases and temperature and humidity on formaldehyde detection.

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