Self-hold dark discharge carbon nanometer pipe film gas sensor and its gas concentration measuring method

Abstract

The invention relates to a method of using a discharge gas sensor to directly measure the density of gas and nano carbon pipe film gas sensor, including the characteristics that: measure breakdown voltage of the sensor by discharge characteristics testing system to acquire one or two or multiple dimensional original model; use interpolation fitting process to build interpolation original model; do monodromy conversion and build the secondary rebuilt model of the sensor; build verse modle of the secondary rebuilt model the sensor is made of two pieces of ITO film conducting glass or two pieces of conducting glass material, whose two poles both hate multiply holes pasting to carbon millimicron pipe film and the distance of poles is structural characteristic parameter.

Description

technical field [0001] The invention belongs to the technical field of gas analysis and detection, and relates to a method for measuring gas concentration with a discharge type gas sensor and a self-sustained dark discharge carbon nanotube (carbon nanotube, CNT) film gas sensor based on the method. Background technique [0002] As people pay more and more attention to the living environment and environmental protection, higher requirements have been put forward for the detection of various toxic and harmful gases, the monitoring of air pollution and industrial waste gas, and the detection of food and living environment quality. In the 1990s, the United States developed the most advanced analyzer in the world so far—the atmospheric pressure ionization mass spectrometer (APIMS), which can detect impurities in gases up to 100×10 -12 range, becoming a solution to a variety of 10 -12 The only means of level gas impurity analysis. The Discharge Ionization Detector (Discharge Ion...

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Problems solved by technology

The biggest problem with these existing technologies is that they require high technical requirements for implementation, are inconvenient to use, and are expensive to analyze, and are not suitable for environmental detection anytime and anywhere.

[0003] In the prior art before the present invention, someone tried to use the discharge type gas sensor as a means of gas qualitative and quantitative analysis, because there is a positive and negative correlation between the breakdown voltage Vs of the discharge type gas sensor and the measured gas concentration , This is because the captured signal is affected by many complex factors (such as temperature fluctuations, humidity fluctuations, atmospheric pressure fluctuations, fluctuations in the amount of residual charge in space, and fluctuations in the intensity of various rays in space, etc.), and is often submerged in noise interference signals. If the useful signal is not separated, the relationship between the breakdown voltage Vs of the sensor and the concentration of the gas to be measured cannot be used for gas type identification and concentration measurement, so it is impossible to use it as a gas qualitative and quantitative analysis based on

So far, the existing technology has not solved the problem of measurement and identification of the signal captured by the discharge gas sensor, so that the discharge gas sensor cannot enter the practical stage, and it still needs to be integrated with a mass spectrometer or chromatograph

For example, the self-sustained dark discharge type gas sensor with a micron-electrode semiconductor silicon material constructed by Dai Pinghu of Zhejiang University and others has a micron-scale curvature radius at the top of the cathode, and a very high electric field is concentrated in a small area with a distance of 50 μm, which can darken the gas under atmospheric pressure. The operating voltage required for discharge is reduced to one-tenth (above 350V) of the usual value (5000-10000V), and the self-sustaining dark discharge I-V characteristics, sensor discharge current sensitivity and response speed of water vapor and 5 kinds of single organic gases are obtained. Such valuable work results, but the sensor belongs to a micron-scale micro-electrode constructed by micro-machining technology MEMS, the working voltage is still high, and the specific feasibility method for measuring the gas concentration is not given, and it has not formed a practical gas sensor

Another example is the carbon nanotube film anode gas sensor developed by Nikhil Koratkar and Pulickel M.Ajayan in Japan. It uses corona discharge as a mechanism and uses breakdown voltage as a characteristic parameter for qualitative measurement of a single gas species. Although multi-walled carbon nanotubes have been studied tube film cathode spacing and breakdown voltage, but did not give a feasible method for measuring a single gas species mixed in the atmosphere, nor did it give a method for quantitatively measuring the concentration of a single gas mixed in the atmosphere, and has not yet constructed Carbon nanotube thin film gas sensor

At present, the methods and corresponding gas sensors that have solved the problem of signal recognition and entered into practical use have not been reported at home and abroad.

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