Pressure transducer and method

摘要

A pressure transducer comprises a series-connected helical coil spring and bellows assembled into the bore of a housing by anchoring the spring and bellows at locations which place them in a state of tension. Expansion and contraction of the bellows reacts against the spring and correspondingly positions a ferrite slug within an inductance coil to cause the inductance thereof to be a function of the pressure differential acting on the bellows. One end of the coil spring is threaded onto a threaded fitting secured to one end of the bellows, and slope calibration of the transducer is accomplished by setting the amount of engagement of the spring with the threaded fitting. Offset calibration can be performed by either of two disclosed techniques, and the offset and slope calibrations can be independently made.