Development of thermal gas mass flowmeter

The measurement principle of thermal gas mass flowmeter was explained in the paper. Design of the thermal gas mass flowmeter based on the MSP430 microcontroller. The flowmeter using assembled platinum-film probe as it's sensor, and its flow measuring circuit has the function of temperature compensation. The flow measuring experiment of the flowmeter was tested on Sonic Nozzle. The results of experimental data processing proved that the flowmeter has a wide measuring range, high accuracy and repeatability. The measuring range was 100∶1. From 0.1 Q
max
to Q
max
, the relative error was less than ±1.5%