Compressibility compensation inside field device using FDT configuration software

This paper presents new compressibility compensation system which consists of FDT (Field Device Tool, IEC62453) standard conforming configuration software and mass flow measurement field device. The configuration software calculates coefficient for compensation from the physical property database inside host computer. The field device dynamically compensates compressibility for process fluid using the coefficient. By this system, even though field device has limited processor power and memory space, compensation is done with full functionality of the physical property database. We have already developed the system for multivariable transmitter and vortex flow meter and confirmed the benefits. We did the field test and confirmed the new compensation system contributed to the natural gas mass flow rate accuracy as excellent as 1% for multivariable transmitter on a UKAS-certified British test line. Regarding the interoperability of the configuration software, we have the certification of FDT standard and confirmed open operational environment. We will extend the functionality in future and contribute to the progress of process automation industry.