Design of a small gas flow calibration facility by piston prover method

In response to the need for portable calibration of small gas flow meters, this study presents the development of a dedicated calibration facility based on the piston prover method. Unlike the vertical piston prover made of glass pipe, the designed facility is a horizontal structure. A photoelectric detection system, equipped with fiber optic sensors, has been developed to achieve the high accuracy required for measuring the measurement time. The device accommodates a flow rate range of 0.1–25slm. Additionally, to facilitate on-site calibration, the device is small and portable also developed a PLC-based control system and a user-friendly interface for data acquisition and control. The experimental device with the automatic calibration control system conducted calibration tests on the two flowmeters, and finally metrologically compared with the sonic nozzle gas low-flow standard device. The experimental results show that the extended uncertainty of the device is 0.46 % ( k = 2). The measurement repeatability is better than 0.13 %, which can effectively meet the calibration requirements of small flow gas measuring equipment.