Research On The Verification Technology Of Diaphragm Gas Meter Indication Error Based On Rotary Volume

With the continuous adjustment of the global energy structure and the rising rate of city gasification,the application of global natural gas resources has entered a period of rapid development.Diaphragm gas meter is the main gas energy measuring instrument,and its further expansion of the production scale is greatly restricted by detection technology and verification speed.To solve the problem of verification inefficiency of diaphragm gas meter,the equivalent rotary volume could be obtained by means of the differential pressure method and double timing method which could detect the inlet and outlet pressure that driven by the movement of the reciprocating part of diaphragm gas meter and then doing self-correlation analysis.And then used the integer multiple of rotary volume as the preset ventilation of small flow point to shorten the verification time.A system of diaphragm gas meter indicating error verification was designed based on the sonic nozzle standard calibration device.This system used IPC as the core,using ARM CortexTM-M4 processor.Each external photoelectric sampler corresponding to the diaphragm gas meter was connected to the STM32 microprocessor with the interrupt function of I/O port to collect the signal time and number of the pulses.The conditioning circuit and AD conversion circuit of the differential pressure sensor output signal was designed,and the conversion data was obtained by the use of single-chip timer capture function and interruption occurrence.Temperature,pressure,humidity and other environmental parameters were collected by the sonic nozzle standard calibration device included with conversion transmitters.The system also included the design of the I/O module,the communication module and power supply module.Verification interface was completed by LabVIEW upper computer software which could orderly transfer data acquisition module and communication module to complete the collection and transmission of data,and complete the subsequent data processing and storage.The experiment results show that the indicating error verification device of diaphragm gas meter based on equivalent rotary volume is stable and reliable which can make the whole process more automated and more efficient.It significantly shortens the indication error verification time of domestic diaphragm gas meter while ensuring the accuracy of the calibration.