A calibration method based on instantaneous flow rate is proposed by utilizing the metrological performance of the output instantaneous flow rate for the thermal sensor.Infrared transmitting and receiving circuits are installed on the main board module of the thermal meter.The data are interacted with the host computer by means of infrared communication to read the instantaneous flow rate displayed by the thermal sensor.The calibration method is based on the sonic nozzle method.The instantaneous flow rate of the gas at the sonic nozzle is read by the lower computer and the indication error is calculated.Program settings communication,preliminary calibration,generating coefficient correction list,writing coefficient,recalibration,judgment a total of six procedures,one key to achieve continuous,batch,automatic calibration of the thermal meter.The instantaneous flow method was used to test the indication error of 0.5 m~3/h flow point of G1.6 gas meter,and the repeatability was 0.053%.Compared with the cumulative flow method,it is improved by 0.05%.The calibration time is shortened by 87%,and the work efficiency is greatly improved.
Industrial Instrumentation & Automation
thermal mass gas meter
cumulative flow rate
instantaneous low rate