On-line compensation in a digital Coriolis Mass Flow meter

For many years it has been demonstrated that the use of digital technology, particularly embedded microprocessors, can improve flowmeter performance i n various ways (e.g. temperature compensation, elimination of drift, genera tion of engineering units, diagnostics). A self-validating or SEVA sensor u ses in-built processing power to generate generic metrics of measurement qu ality, based on on-line uncertainty. This uncertainty includes all factors effecting the on-line measurement, including diagnostics but also manufactu ring aspects such as the components used and the characterisation procedure . This paper describes a prototype SEVA coriolis mass flow meter transmitte r built primarily from digital components, which provides compensation for both faults and manufacturing limitations. A technique to compensate for dr ift and imbalance in the transmitter front-end circuitry is described in de tail. The prototype has been developed using a hardware/software co-design approach in which virtually all aspects of instrument design are described in software, but which can be implemented flexibly in either hardware or so ftware according to economic requirements. This approach offers manufacture rs the opportunity of incorporating the latest components into their produc ts rapidly in order to remain competitive. (C) 2001 Elsevier Science Ltd. A ll rights reserved.