The Development Of The Gas Flow Field Calibration Device

In recent years,due to the implementation of the west to east gas pipeline project in China,many cities and regions began to widespread use of natural gas.With the development of fuel gas,the demand of online calibration test instrument has become more and more urgent.The imported field device and model are unable to meet the vast majority of pipe network to be tested in our country.lt is urgent for us to find a field measuring modle to adapt the current market environment,and provides the technical basis for the development and establishment of device like this.This article comparedthe advantages and disadvantages of several different working principle of the altrasonic flowmeters,and then choose the time difference measurement as the based principle.During the experiment,analyze the factors that affect the accuracy of the results.Including the installation of the transducer,the parameters of the pipe and the length of the straight pipe,etc.Through the test,improve the design of the whole device,and realize the on-site verification for gas meter.In terms of measurement control, the hardware part mainly include signal conversion and output control module.The ultrasonic flowmeter in the standard device output analog signal and the signal displayed on the computer is digital.So we put a data acquisition module to realize the A/D convision and data processing,and reflect the flow information to computer.The software part,use the Visual Basic language,and design several functional interface to control the verification time and points in the process of mearement.and observe the flowmeter through the interface.Finally,collect the data information and save them in the database,which is convenient for the staff to check and issue the test report in future.In the end of the experiment,put the data to error processing and uncertainty analysis,proved that the device is qualified for the field calibration device.In order to improve the precision of the device,adopt many anti-interference method,which is helpful for the stability of the whole process,provides a technical basis for the verification of field instruments and remote monitoring,and the device has the pritical signficance.