A Cyclic Self-Calibration Method Based on a High-Precision Piston and Standard-Meter Water Flow Prover

Area of Science:

• Metrology
• Fluid Dynamics
• Calibration Techniques

Background:

• Standard meter water flow provers are common but require time-consuming off-site calibration.
• Off-site calibration introduces deviations due to installation and operational differences.
• Piston provers offer high precision and traceability, while standard meters provide good repeatability.

Purpose of the Study:

• To develop an in situ method for calibrating standard meters using piston provers.
• To enable value transfer from high-precision piston provers to a wide range of standard meters.
• To improve the efficiency and accuracy of water flow measurement calibration.

Main Methods:

• Proposed a cyclic self-calibration method for in situ value transfer.
• Integrated standard meters and transfer meters in series and parallel configurations.
• Analyzed uncertainty transfer using error transfer theory and conducted experimental validation.

Main Results:

• Demonstrated the feasibility of the cyclic self-calibration method.
• Extended high-precision piston flow rates (0.005–4 m³/h) to standard meters (4–1250 m³/h).
• Achieved an expanded uncertainty of better than 0.20% (k=2) for the water flow standard device.

Conclusions:

• The cyclic self-calibration method is a viable approach for in situ calibration of water flow standard meters.
• This method enhances calibration efficiency and accuracy by leveraging piston prover precision.
• The developed method effectively bridges the gap between high-precision piston provers and wide-range standard meters.