Abstract: A transducer monitoring system includes a transducer assembly positioned at a remote location which operates to measure one or more separate physical phenomena. The transducer assembly is coupled to a central location, such as at the top of an oil drilling platform, by means of a single conductor cable. The transducer assembly comprises only passive components, including a stepper switch for separately selecting each of said transducer elements and for enabling current applied to said cable and transducer assembly to generate an output voltage representative of the present state of the resistance of each such transducer element. The improved invention requires only a single constant current pulse periodically applied to the cable to both generate said output voltage and to switch the stepper switch to the next contact. A calibration circuit that measures temperature effects on the transducer assembly and cable is also included.

Abstract: A transducer monitoring system includes a transducer assembly positioned at a remote location which operates to measure the change in at least two separate physical phenomena. The transducer assembly is coupled to a central location, such as at the top of an oil drilling platform, by means of a single conductor with a grounded shield. The transducer assembly includes a stepper switch for separately selecting each of said transducer elements and for enabling current applied to said cable and transducer assembly to generate an output voltage representative of the present state of the resistance of each such transducer element. The improved invention requires only a single constant current pulse to both generate said output voltage and to switch the stepper switch to the next contact. Calibration and comparison resistors are also included in said transducer assembly.