PRESSURE TRANSMITTER WITH STRESS ISOLATION DEPRESSION

摘要

A PRESSURE TRANSMITTER HAS A PRESSURE TRANSDUCER IN A TRANSMITTER HOUSING. THE TRANSMITTER HOUSING INCLUDES A GROOVE OR A NOTCH DEFINING A FLEXURE CLOSELY PROXIMATE A HOUSING OUTER RIM. THE OUTER RIM RECEIVES A LARGER CLAMPING FORCE FROM A FLANGE AND IS DEFLECTABLE ABOUT THE FLEXURE FOR REDUCING TRANSMISSION OF AXIAL AND RADIAL COMPONENTS OF THE CLAMPING FORCE FROM THE HOUSING OUTER RIM TO THE TRANSDUCER, WHICH FORCES CAN CAUSE DISTORTIONS TO THE PRESSURE TRANSDUCER. UNEVENLY DISTRIBUTED CLAMPING FORCES CAUSED BY DIFFERENTIAL THERMAL EXPANSION OF THE FLANGE, BOLTS AND HOUSING, ARE ISOLATED FROM THE TRANSDUCER THEREBY REDUCING MEASUREMENT ERRORS. FURTHER TRANSMISSION OF HYSTERETIC RADIAL FORCES FROM THE TRANSMITTER HOUSING TO THE TRANSDUCER CAUSED BY FRICTION WHEN THE FLANGE SLIDES ACROSS THE PRESSURE TRANSMITTER HOUSING, EACH HAVING DIFFERENT THERMAL COEFFICIENTS OF EXPANSION, IS ALSO REDUCED. SEVERAL TYPES OF PRESSURE TRANSDUCERS INCLUDING CAPACITIVE CELL TRANSDUCERS CAN BE IN THETRANSMITTER HOUSING FOR PROVIDING A PRESSURE OUTPUT INDICATIVE OF LINE AND DIFFERENTIAL PRESSURE.(FIG. 3)