This project seeks to reduce the frequency of the above recalibration cost for installed ultrasonic meters and turbine meters, by increased confidence in the meter accuracy. Work is proposed that will develop an innovative approach to the calculation of uncertainty. The tool will include the automatic selection of the uncertainty values for instruments typically used by National Grid. Consideration shall be given to current transmitters as well as to the transmitters with HART technology. The tool will use a finite difference method to determine the uncertainty & error contributions of the measurements to the overall uncertainty and error in volume flow and the use of the full ISO 10723 approach for composition uncertainty. The tool will also separate the uncertainties associated with barriers and flow computer inputs.

Benefits

If successful, the technique will allow error and bias to be monitored against MPE (maximum permissible error) and MPB (maximum permissible bias), to avoid costly annual re-calibrations where these are demonstrated to be unnecessary.