Dual-channel Gas Mass Flow Meter

The gas is generally measured in volumetric flow. But the gas volumetric flow is often meaningless because the gas volume varied greatly with the change of temperature and pressure especially for the mixed gas which has multi-component Even if the process conditions are relatively stable, it is very difficult to precisely measure the mass flow with the existing mass flowmeter. So measuring the mass flow of the multi-component gas has been an intractable problem in flow measurement field.The mass flowmeter introduced in this paper has the twin channel signal detection system and can directly measure the mass flow of all kinds of gas, which is independent of the component, temperature and pressure. This mass flowmeter has multi-signal generator which can generate the differential pressure and the vortex frequency signals at the same time. According to these two signals, we can calculate the mss flow. On the basis of many related materials, we design a trapezidal multi-signal generator and the corresponding detection circuit After this, we have verified the mechanism of this mass flowmeter by the experiments. Micro-controller PIC16C74A serves as the kernel chip of the hardware circuit, the peripheral chips include display module, E2PROM, key-press and so oa The software includes the following functions: calculating the instant mass flow and accumulated flow, displaying and saving the accumulated flow value, modifying the instrument parameters and saving them, as well as alarm displaying. When the hardware and software completed, we have made the simulation tests which prove that the system meets the specificatioaTwin channel gas mass flowmeter has pioneered a new way for gas mass flow measurement and has solved a problem in flow measurement field.