Constant-temperature and constant-humidity carbon dioxide sensor device and detection method thereof

Abstract

The invention discloses a constant-temperature and constant-humidity carbon dioxide sensor device and method. The constant-temperature and constant-humidity carbon dioxide sensor device comprises a sampling gas chamber, an infrared light source, a dual-channel thermopile detector, a temperature and humidity sensor, a motor, a driving circuit and a single chip microcomputer, the device further comprises an air pump, a pressure reducing valve, a sealing cup filled with water and an air drying pipe. The interior of the sampling gas chamber is of a reflective flat conical structure, the gas chamber is centrosymmetric, the periphery of the gas chamber is wrapped with a PI electric heating sheet and a refrigeration sheet, meanwhile, the periphery of the gas chamber is provided with a gas inlet and a gas outlet, and the gas inlet is connected with the gas drying pipe containing a molecular sieve; one end of the sampling gas chamber is provided with an infrared light source, the other end of the sampling gas chamber is packaged with a dual-channel thermopile detector, and the detector is provided with two paths of light intensity induction windows which are respectively provided with a reference light filter and a measurement light filter; the detector outputs two paths of electric signals, and the electric signals are transmitted to the single-chip microcomputer after passing through the filter amplification circuit and the A / D conversion circuit and then transmitted to the terminal through the upper computer. The invention has the advantages of good processing stability, good reflection performance, reflection reduction and accuracy improvement.

Description

technical field [0001] The invention belongs to the technical field of gas sensors, in particular to a carbon dioxide sensor device with constant temperature and humidity and a detection method thereof. Background technique [0002] Carbon dioxide is an important part of gas, which plays a wide and important role in daily life and industry, and the control of carbon dioxide concentration is also an important indicator for the application of carbon dioxide, so real-time, efficient and accurate detection of carbon dioxide is also more important . At present, the detection methods for carbon dioxide mainly include electrochemical methods, electron capture methods, ultraviolet ionization methods, and non-dispersive infrared absorption methods. [0003] Among them, the non-dispersive infrared absorption method is favored in the field of carbon dioxide gas detection due to its advantages of high sensitivity, wide detection range, and strong anti-interference. However, the applic...

AI Technical Summary

Problems solved by technology

However, the application of non-dispersive infrared absorption method in the actual measurement of carbon dioxide is easily affected by the environment, especially the temperature and humidity of the environment have a greater impact on the detection results

[0004] First, when the ambient temperature changes, the spectral characteristics of carbon dioxide gas itself will change, resulting in a decrease in the absorption efficiency of infrared light and a shift in the center wavelength of the filter, resulting in a large error in the detection result of carbon dioxide concentration

[0005] Second, changes in humidity will affect the infrared absorption frequency of carbon dioxide

Untreated carbon dioxide gas is generally attached with a large amount of water vapor. When the infrared light passes through the carbon dioxide, it will be scattered due to these water molecules. The secondary radiation diffusion of the infrared light source will cause loss, and the detection result of the carbon dioxide concentration will also have a large error.

Images