Multi-working-mode gas flowmeter and gas flow measuring method

Abstract

The invention relates to a multi-working-mode gas flowmeter and a gas flow measuring method. The multi-working-mode gas flowmeter comprises first pressure gauges, a reference chamber, a comparison chamber, at least two parallel branches, a calibrating chamber, a variable-volume chamber, a fixed-volume chamber, a third stop valve and a differential pressure gauge, wherein the first pressure gauges are serially connected to one another; each branch is provided with a volume chamber; the volume chamber of at least one branch is connected with a small-diameter connecting pipe; the variable-volume chamber is connected with the comparison chamber and has a moving structure capable of adjusting the volume of the volume chamber; the fixed-volume chamber is connected between the comparison chamber and a flow distributing circuit; the third stop valve is connected between the reference chamber and the comparison chamber; and the differential pressure gauge is connected with the reference chamber and the comparison chamber. The gas flow measuring method comprises the following steps of vacuumizing the gas flowmeter; filling gas in the flowmeter; measuring the pressure of the filled gas; and measuring and calculating the flow of the gas. The flow distributing circuit comprises at least two parallel branches, a stop valve is arranged between every two parts, different parts can be combined, so that the gas flowmeter can measure the flow of gas in a plurality of working modes, and the range ability is improved.

Description

technical field [0001] The invention relates to the field of gas flow measurement, in particular to a multi-working mode gas flow meter and a gas flow measurement method. Background technique [0002] A gas flow meter is a device for measuring and providing gas micro-flow. It is the basis for establishing gas micro-flow measurement and calibration standard devices. Accurate measurement of gas flow is of great significance. With the development of my country's aerospace industry, the development of manned spacecraft, launch vehicle and other technologies has expanded the range of gas micro-flow measurement and calibration, the extension of the minimum gas flow measurement and calibration lower limit, and the accuracy of gas micro-flow measurement instruments, Reliability requirements are getting higher and higher, so it is necessary to develop a gas microflowmeter with smaller measurement uncertainty, wide measurement range, and lower measurement limit. Since most of the gas ...

AI Technical Summary

Problems solved by technology

Since most of the gas micro flowmeters in the past have a single working mode, the measurement range is narrow and the measurement uncertainty is large, different devices are required to measure the gas micro flow in different ranges, and effective comparison cannot be carried out. The key parts of the flowmeter are made of non-metallic substances, which leads to low baking temperature, which makes the overall degassing of the gas micro-flowmeter insufficient. When measuring the gas flow, the wall is deflated, which makes it difficult to extend the lower limit of the flow of the gas flowmeter.

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