Calibration method for flow calibration coefficient of multi-component mixed gas

Abstract

The invention discloses a calibration method for a flow calibration coefficient of multi-component mixed gas. The method comprises the following steps: (1) taking a mass spectrum as a gas flow detector, and selecting a gas which does not react with any component in the mixed gas as a reference gas; (2) injecting a single reference gas by using a standard flow controller, injecting a mixed gas through a to-be-detected flow controller or a flow meter, mixing the injected reference gas and the mixed gas, and detecting the mixture by using a mass spectrum; (3) according to the mass spectrum characteristic chromatograms and the relative sensitivity of the different components in the mixed gas, obtaining the actual flow of the different components through a mass spectrum quantitative analysis technology, wherein the mass spectrum quantitative analysis technology is an equivalent characteristic spectrum method; (4) summing and calculating the actual flow of the mixed gas; and (5) comparing the actual flow with the numerical value of the flow controller or the flow meter to be detected to obtain a calibration coefficient of the flow controller or the flow meter to be detected.

Description

technical field [0001] The invention relates to the technical field of gas detection, in particular to a calibration method for flow calibration coefficients of multi-component mixed gases. Background technique [0002] Gas flow meters and flow controllers are widely used in all walks of life, and the accuracy of their detection and control of flow is very important for various applications. However, conventional gas flow meters / flow controllers are based on standard gas types (such as N 2 ) as a benchmark, the conversion factor F of the standard gas is calibrated under the standard state std , the calibration coefficient ε of other gas species i (such as CO, etc.) is calibrated relative to the standard gas i , the product of the two constitutes the actual transformation parameter S of gas i i . with regular N 2 Take the flow controller as an example, the conversion factor is It has been set by the equipment manufacturer, if the detection signal is S, N 2 The volume ...

AI Technical Summary

Problems solved by technology

[0011] However, the above two types of methods all have relatively large technical defects, mainly manifested in the existence of principle errors

The first type of method uses the indirect estimation of the gas state equation, but the gas state equation itself is established for the ideal gas. For the mixed gas, the gas state equation itself needs to use a correction coefficient, so there is a big problem in principle, this problem directly reflected in the estimated calibration coefficient ε i There is an unknown error

The problem with the second type of method is that the dynamic change of the flow itself is replaced by an approximately reasonable flow time average value. For this reason, multiple long-term detections are required to weaken the objective error of this type of method; for small-range flowmeters or flow control device, in the detection calibration calibration coefficient ε i It will also introduce problems such as size effect, dead volume, diffusion, etc., and its accuracy is more difficult to effectively guarantee

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