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Thick film circuits were developed for temperature compensating of semiconductor strain gauges and for connecting the gauges to amplifiers in electronic pressure and differential pressure transmitters. In each circuit, ten Au pads for Al wire bonding and thirteen Ag/Pd pads for soldering must be fabricated on a small substrate. The results of the research are shown below.(1) The resistance values and the thermistor constants required for the thermistors are 0.9 ± 0.09 kilo-ohm and 2500 ± 40 Kelvin, respectively. Those characteristics are realized by developing a paste composition composed of a new spinel type oxide (Mn1.6Co0.8Ni0.35Ru0.25O4) RuO2and glass.(2) Accelerated life tests of the thick film thermistors reveal that the resistance drift rates of the thermistors are less than ±0.02 %/year at 120°C.(3) Life tests clarify that the wire bonding pads fabricated by using ESL 8882 Au paste keep more than 4 grams in pull strength, and that the soldering pads fabricated by using Sumitomo CLP 495A Ag/Pd paste are more than 1 kilo-gram in pull strength.(4) The temperature dependence of zero shift and span shift in the pressure transmitter are suppresed within ±0.2% between –40°C and 120°C by using the thick film circuit developed.

Bridge of semiconductor strain gauges with a silicon diaphragm is very useful for pressure measurement and has currently wide applications for many fields. However, these gauges have miss matchings of resistance and temperature coefficients. These facts bring difficulties for use in a wide temperature range with high accuracy. This paper presents the precision and wide range temperature compensation algorithm for semicoductor strain gauge bridge by the analogue circuit technique.

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This patent relates to wheels that are provided with resonant absorbers for the purpose of reducing the screech-noise-producing axial vibrations of the wheels. Each absorber here is composed of several tongues which are separated from one another by layers of damping material, and each of these tongues is tuned to a different natural frequency of the wheel. Sets of these absorbers may be mounted near the wheel tire, either directly on the wheel, or on annular skirts attached to it.--EEU 4,361,213 43.40.Trn VIBRATION DAMPER RING This patent pertains to seals between rotating and stationary members of rotating equipment, such as turbine engines. The seals here are mounted on extensions, such as flanges, in order to obtain increased friction.--EEU 4,369,398 43.40.Vn METHOD AND APPARATUS FOR