Gas-mass-flow up-down-stream temperature distribution secondary differential measuring method, sensor and flowmeter

Abstract

This invention relates to a secondary difference measurement method, sensors and flow meters for temperature distribution of the upper and lower reaches of a gas mass flow including a temperature-adding element and a temperature test element set symmetrically at either side of the temperature-adding element, namely an upper reaches test element and a lower reaches test element characterizing that said temperature adding element is connected with the constant power source, the two test elements are connected with the input ends of two signals of the difference operation circuit, the output of which is connected with a central process unit, which has small influence on the linearity of low speed segments by carrying secondary difference operation to the difference value of temperature variance of the upper and lower reaches, the saturated point of the relation curve of the flow rate of the gas mass flow and output voltage is push forward to enlarge the range sphere and linearity.

Description

technical field [0001] The invention relates to the field of mass flow detection, in particular to a secondary differential measurement method for upstream and downstream temperature distribution of gas mass flow, a sensor, and a flowmeter. Background technique [0002] Thermal gas mass flow measurement is a technology that uses the principle of heat transfer, that is, the heat exchange relationship between the flowing fluid and the heated object in the heat source fluid or the heating body outside the measurement tube to measure the flow rate. It is mainly divided into two types: anemometer and calorimetric. The working principle of the anemometer is based on the King's Law theory proposed in 1914. This measurement method is based on the heat dissipation degree of the heating wire under the fluid flow. The measurement principle of calorimetry is to detect the flow velocity by detecting the temperature distribution on both sides of the heat source of the heating element dur...

AI Technical Summary

Problems solved by technology

[0008] Another purpose of the present invention is to solve the technical problems existing in the prior art that the measurement accuracy is not high, it is easy to cause errors, and it is not sensitive to low-speed sections; it provides a gas with high measurement accuracy, can effectively eliminate errors, and has high sensitivity. Mass flow upstream and downstream temperature distribution secondary differential measurement method, sensor, and flowmeter

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