An FPGA implementation of a digital Coriolis mass flow metering drive system

Coriolis mass flow metering provides a direct measurement of mass flow and is generally regarded as the most accurate and precise flow technology in common use in industry. This paper describes the role of the field-programmable gate array (FPGA) hardware, which is programmed using the Handel-C language, in the implementation of a "digital" Coriolis meter, which replaces the conventional analog positive feedback system used to maintain flowtube oscillation. The FPGA is coupled to a microprocessor, which carries out conventional measurement tasks and selects the drive parameters to be used by the FPGA. The resulting meter is able to maintain the operation in more difficult process conditions, including two-phase flow, which has previously caused Coriolis meters to cease oscillation. The system described in this paper is used in a commercial meter that has been successfully applied to two-phase industrial applications.