Gas sensing property response curve testing apparatus

Abstract

The invention discloses a gas sensing property response curve testing apparatus. The bottom of a sample carrier platform is provided with a heating sheet, and the top surface of the sample carrier platform is used for carrying a gas sensing material to be tested. An inner cavity of an inner cover is provided with a stirring support, a group of driven magnets is circumferentially and fixedly arranged on the outer end of the stirring support, the driven magnet is a pole-N magnet, and an outer circumferential surface of the driven magnet is in rotating fit with the inner wall of the inner cover.According to the technical scheme, the non-detachable transparent inner cover is additionally arranged, so that the influence of external temperature on the gas sensing characteristics can be avoided.Meanwhile, by adding the detachable non-transparent outer cover, the influence of external light on the gas sensing characteristics can be insulated, and the near-surface gas state of the gas sensingmaterial to be tested is enabled to be stable. Moreover, a heating rod is adopted in the technical scheme to scan the near surface above the gas sensing material to be tested in a reciprocating manner, so that the 'poisoning' phenomenon of the gas sensing characteristics can be eliminated. In addition, the outer cover is provided with a light loading opening, so that the light of a given wavelength can be loaded.

Description

technical field [0001] The invention belongs to the field of gas-sensitive materials and gas-sensitive sensors, and in particular relates to a gas-sensitive characteristic response curve testing device, which can also be used in other fields related to gas pressure and components. Background technique [0002] As is well known to those skilled in the art, a gas sensor is made of a gas-sensitive material and is used to measure the type, concentration and composition of a gas, to detect a specific composition in the gas, and to convert the composition parameter into an electrical signal. Or device, it is also called gas sensor. The applications of gas sensors mainly include: carbon monoxide gas detection, gas gas detection, gas detection, Freon (R11, R12) detection, ethanol detection in exhaled breath, human oral bad breath detection, etc. [0003] The gas-sensing characteristic response curve of the gas-sensing material is an important parameter of the gas-sensing material, ...

AI Technical Summary

Problems solved by technology

[0005] 1. Since the existing test device has an open structure and is in contact with external temperature, light and impurities, it is impossible to isolate the influence of external temperature, light and impurities on the gas-sensing characteristics, resulting in the test accuracy of the gas-sensing characteristic response curve not tall

[0006] 2. The existing structure is an open structure, and the gas-sensitive material has adsorption on gas, which leads to the unstable state of the gas near the surface of the gas-sensitive material to be tested during the test, with large randomness and irregular changes, which leads to test results Low reliability and poor repeatability of test data, making gas sensitivity testing meaningless

[0007] 3. In the process of academic research, we found that in some test environments, the gas concentration and temperature field near the gas-sensitive material to be tested need to be uniform, so as to prevent the uneven gas concentration and temperature field from interfering and hindering the test. However, the existing technology can't solve

[0008] 4. During the test, it may be necessary to load light of a specific wavelength under the premise of shielding the external temperature, light and impurities in order to study the influence of light on the response curve of the gas sensitivity characteristic. However, the existing technology cannot meet this technical requirement at all.

[0009] 5. The test object targeted by some gas-sensitive materials to be tested is liquid (such as alcohol) at room temperature. During the test, it needs to be heated to make it into a gaseous state, and it must be prevented from forming droplets after liquefaction during the test. Thereby ensuring the smooth progress of the gas sensitivity test, but the existing technology cannot realize

[0010] 6. Since the gas-sensitive material to be tested has an adsorption effect on gas, the phenomenon of "poisoning" of the gas-sensitive characteristic will occur, resulting in a decrease in test sensitivity and accuracy

In order to overcome the above defects, it is mainly realized by directly heating the sample and high-pressure blowing. Directly heating the sample will cause the temperature of the gas-sensitive material to be tested to change, which will lead to a change in the test conditions, which will in turn affect the test. precision

Although the way of high-pressure blowing can eliminate the "poisoning" phenomenon of gas-sensitive characteristics, it needs to use high-pressure gas, which will lead to restrictions on the use environment (such as underground mines or special confined spaces)

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