LIQUID-TO-GAS DIFFERENTIAL PRESSURE TRANSMITTER WITH SMALL HYDROSTATIC ERROR

A design is described for a device which transmits steady-state differ ential pressure from a liquid process to a gas differential pressure s ignal. By appropriate design, the hydrostatic error inherent in liquid -to-gas pressure transmission can be made negligibly small in relation to the accuracy of the differential pressure transducer. The instrume nt is a design modification of the ''gas trap'' method of pressure mea surement for liquid-metal systems. The design described results in a s imple, inexpensive, and easy to implement technique for liquid-metal d ifferential pressure measurement, and, by appropriate design, with a n egligible hydrostatic error. The design and implementation of such a s ystem was undertaken with highly satisfactory results. Operational asp ects of such a system are described. The design is applicable to a sys tem where highly accurate steady-state differential pressure measureme nts are needed, while avoiding introduction of the process directly wi thin the differential pressure transducer. (C) 1997 American Institute of Physics.