HM 45. Statistical control of measuring instruments using control charts – simplified method

Overview:

This publication provides guidance for the adoption and implementation of statistical meter control charts. It is based on the statistical concepts used in ISO 4124 – Statistical control of dynamic liquid hydrocarbon volumetric metering systems. The document provides a simplified version suitable to those situations where insufficient computer capacity, lack of local expertise or limited human resources is encountered.

This second edition of HM 45 includes a number of updates. A new Annex B provides a more rigorous statistical approach to using meter control charts and includes material that was previously included in HM 25. Statistics for static and dynamic measurement.

The procedures contained in this document could, in principle, be applied to any type of metering installation. However, they are intended for use in situations where instruments are calibrated, proved or verified regularly and frequently, such as in fixed installations incorporating a proving system.

Although this publication has been primarily produced to apply to flow meters, the principles outlined can be applied to monitor the performance of secondary measurement instruments such as pressure transmitters, temperature measurement devices and densitometers.