Subtractor-based design of anti-interference circuits of electrochemical formaldehyde sensors

Abstract

The invention discloses a subtractor-based anti-interference designing method of electrochemical formaldehyde sensor hardware. The electrochemical formaldehyde sensor hardware comprises two electrochemical formaldehyde sensors in the same type, an operational amplifier and a semi-permeable membrane, wherein one electrochemical formaldehyde sensor serves as a sampling circuit and is placed in to-be-tested environment; the other electrochemical formaldehyde sensor serves as a comparison circuit and is also placed in the to-be-tested environment, and the semi-permeable membrane covers an air inlet so as to prevent other components of formaldehyde from causing influence on output; the operational amplifier serves as a subtractor; data output by a sampling sensor is input into an in-phase input end of the subtractor; data output by a comparison sensor is input into an anti-phase input end of the subtractor, so that the interference components generated by the environment factors in the sampling signals can be filtered, thereby solving the defect that the conventional thermistors and hygristors serve as compensation circuits of formaldehyde sensors and greatly improving the accuracy and the reliability of formaldehyde detection.

Description

technical field [0001] The invention relates to a portable formaldehyde detection method, in particular to a formaldehyde detection method based on a subtractor hardware anti-interference circuit and a digital filter, belonging to the technical field of detection Background technique [0002] Formaldehyde is a colorless gas with a special pungent smell, which has a strong irritating effect on human eyes and nose. It is mainly used in the textile industry and wood industry, and is an important organic solvent and chemical raw material. At present, the wooden floors and wall coatings widely used in home decoration contain a large amount of formaldehyde, which causes the problem of formaldehyde pollution in newly renovated houses to be very serious. If you stay in an environment where formaldehyde exceeds the standard for a long time, it will cause chronic respiratory diseases and may cause nasal cancer, and may cause leukemia. At present, the main detection methods for forma...

AI Technical Summary

Problems solved by technology

At present, the main detection methods for formaldehyde are: spectrophotometry, gas chromatography, liquid chromatography, etc. Although these methods may have high detection accuracy, their operation methods are complicated and are not suitable for popular detection.

The electrochemical formaldehyde sensor detection method is flexible and has the advantages of being portable, but the electrochemical sensor is easily affected by factors such as temperature and humidity in the environment in actual use, resulting in large measurement errors and low accuracy.

Although the use of thermal and humidity sensitive resistors can compensate measurement errors to a certain extent, it is difficult to meet the requirements in actual use.

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