Abstract: A pressure or differential pressure detector is hardened to be suitable for use in a hostile environment, for example, under high pressure, temperature, and radiation conditions which could possibly be present in the containment vessel of a nuclear generating plant. A linear variable differential transformer (LVDT) disposed within a detector housing is designed to sustain temperatures up to or exceeding 500.degree. F. A signal detecting and conditioning circuit disposed remote from the detector housing includes demodulator means for producing X and Y demodulated signals respectively from A and B secondary windings of the LVDT, a summing circuit for producing a temperature analog voltage X+Y, a subtractor for providing a differential pressure analog voltage X-Y, and a multiplier for multiplying the differential pressure analog voltage X-Y by a temperature compensation voltage X+Y-Ref based on the temperature analog voltage to provide a resulting temperature-compensated differential pressure analog signal.