Large Metering Calibration

The project involved the establishing the procedures required to undertake accuracy calibrations as well as identify associated criteria required to develop a Quality System for the ongoing calibration and testing of large meters. Criteria for establishing the various procedures, methods, personnel, equipment and engineering infrastructure will be identified in context of the following:

• Management requirements (A synopsis of the management requirements was provided); and
• Technical requirements (Sources of uncertainty in an in situ calibration system were identified).

These criteria will be identified within the context of AS/ISO 17025 (2005) and associated metrological requirements of the National Association of Testing Authorities (NATA) and the National Measurement Institute (NMI) of Australia.

A comprehensive literature review was undertaken relevant to the development, implementation and accreditation of an in situ calibration system.

The emphasis of an in situ calibration system is to eventually establish an accredited flow reference standard that could be used as a benchmark to determine the error of measurement of permanently installed large flow meters. A summary example of a procedure for the in situ calibration of permanent in-line water meters was also provided.

Gaps were identified in the compliance of a pragmatic in situ calibration system compared to the mandatory Australian metrological requirements.

Recommendations related to the potential establishment of an in situ calibration system that would provide the necessary confidence in the data derived from large meters were provided. This included the development and implementation of a Quality System described in an AS / ISO 17025 based Quality Manual and accredited by National Association of Testing Authorities (NATA).

For more information, please contact:

Email: Edgar Johnson