Abstract: A capacitance transducer construction for borehole pressure measurements where the support for one of the capacitor plates sets is mounted in an independent structure which is attached through a temperature compensating means to the support for the other capacitor plates for eliminating stress effects. Electron bonding of materials having graduated coefficients of friction is utilized to minimize stress effects.

Abstract: A self-contained, down hole powered electrical system in which the available power of a battery source is matched by a power conversion means to the power required in the down hole equipment and the power conversion means provides a regulated voltage output.

Abstract: A capacitance type pressure transducer for pressure measurements for accurate pressurements under differing temperature and pressure conditions having a mechanical construction wherein the displacement characteristics of the transducer as a function of temperature are equated to a compensating change in capacitance as a function of temperature so that changes in temperature do not change the accuracy of the transducer response; a mechanical configuration of the transducer to provide equivalent thermal pathways in the transducer to equalize transient temperature effects upon the transducer and a mechanical design to provide a structural capacitance relationship basically independent of gravitational effects due to positional location of the transducer.

Abstract: The disclosure relates to a capacitive pressure transducers which includes a flexible diaphragm. The flexibility of the diaphragm varies with temperature and thus different capacitance values result from the same pressures at different temperatures. To compensate for the variance of flexibility and capacitance values parts of the transducer are chosen with respect to specific temperature of coefficients.

Abstract: A method and apparatus for testing for leaks in a test item which has a temperature different from ambient temperature in which the test item is sealed at atmospheric pressure and the pressure of the sealed air in the test item is measured. The rate of change of the pressure of the sealing air due to the non-ambient temperature of the test item is calculated for providing a temperature correction signal proportional to the temperature of the test item and the temperature correction signal is stored. The test item is then subjected to a leak test pressure, any change in the pressure of the pressurized test item is measured and the stored correction signal is applied to the pressure measurement for determining the extent of any leak in the test item while compensating for the temperature of the test item.

Abstract: A measuring system based on using a ratio of variable capacitance measurements derived from alternate sampling and referencing of at least two capacitance devices and use of a single channel for the capacitance outputs so that the measurements are basically independent of the circuit components, supply voltage, temperature drift problems. The measurements can be high resolution digital signals.