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Dory Launching, circa 195

Trielectrode capacitive pressure transducer

A capacitive transducer and circuit especially suited for making measurements in a high-temperature environment are described. The transducer includes two capacitive electrodes and a shield electrode. As the temperature of the transducer rises, the resistance of the insulation between the capacitive electrode decreases and a resistive current attempts to interfere with the capacitive current between the capacitive electrodes. The shield electrode and the circuit coupled there reduce the resistive current in the transducer. A bridge-type circuit coupled to the transducer ignores the resistive current and measures only the capacitive current flowing between the capacitive electrodes

Vibrating-membrane electrometer has high conversion gain

Vibrating-membrane transducer in a circuit can measure current below 10 to-the-minus 17 ampere. This electrometer has a high conversion gain and a minimum internal power consumption

Vibrating element electrometer with output signal magnified over input signal by a function of the mechanical Q of the vibrating element Patent

Vibrating element electrometer producing high conversion gain by input current control of elements resonant frequency displacement amplitud

Miniature capacitive accelerometer is especially applicable to telemetry

Capacitive accelerometer design enables the construction of highly miniaturized instruments having full-scale ranges from 1 g to several hundred g. This accelerometer is applicable to telemetry and can be tailored to cover any of a large number of acceleration ranges and frequency responses