Establishment of Verification Device for Natural Gas Flow Integration Meters

The natural gas flow integration meter is a secondary instrument used for natural gas metering. Its function is to process and calculate the signals transmitted from primary instruments on site, such as temperature transmitters, pressure transmitters, gas chromatographs, flowmeters, etc., and finally calculate the natural gas flow or energy under standard conditions. In order to ensure the accuracy and consistency of the measurement results of the measuring instruments and maintain the economic interests of both the supplier and the demander, it is necessary to carry out the verification and calibration of the flow integration meters. According to JJF 1003-2016 Flow Integration Meters, a set of verification devices for natural gas flow integration meters has been established. The device is composed of three multi-functional calibrators, which output the corresponding standard signals of the temperature transmitter, pressure transmitter, and flowmeter to the flow integration meter. After receiving the standard signals, the flow integration meter converts them into the target values, and the measurement errors of each channel are calculated according to JJG 1003-2016. Through the repeatability experiment of temperature, pressure, and flow channels, the uncertainty of the measurement results has been evaluated. The expanded uncertainty of the verification device is 0.14%, which can be used to verify and calibrate flow integration meters with accuracy class 0.5 and below. The standard device has passed the measurement standard assessment organized by State Administration for Market Regulation and solved the problem of tracing the value of the flow integration meter at the natural gas station. Based on the verification device, the matters needing attention and problems in the verification process of the flow integration meters are discussed, and suggestions for the revision of the verification regulations are put forward.