To solve the problem of temperature drift of thermal flowmeter,the structure of thermal flowmeter in constant power mode was proposed,and its digital calibration method was studied.Compared with conventional thermal flowmeters,an environ-mental probe was added,which was embedded in the fluid pipe wall.The sensors were insulated from each other.The voltage sig-nal measured by the environmental probe and the temperature sensor was calibrated digitally in real time.The flowmeter was test-ed by the sonic nozzle gas meter inspection device.The test results show that the error rate is controlled within 0.5%in the flow range of 0.016～0.25 m3/h,and the error rate is controlled within 1.0%in the flow range of 0.25～6 m3/h,and the temperature drift phenomenon is effectively improved.
维普
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