Mks Instruments, Inc.

Leonid Mindlin

Claudia Quigley

Santhi E Mathew

James M Poulin

Kerry S Lahey

Donald K Smith

Wayne C Haase

Stephen F Horne

Paul M Chizinski

J Robert Maxwell

Philip J Maiorana

Gardy St Paul

Eric R Taranto

Stephen D Blankenship

Claudia J Quigley

A heater is disclosed for use with pressure transducers. The disclosed heater includes a first heating element and a second heating element. The first heating element is characterized by a first electrical resistance. The second heating element is characterized by a second electrical resistance. In preferred embodiments, the first electrical resistance is different than the second electrical resistance. The disclosed heater can be used to accurately heat a pressure transducer to at least four different operating temperatures by selectively (a) connecting the first heating element to the transducer temperature control circuitry, (b) connecting the second heating element to the transducer temperature control circuitry, (c) connecting the first and second heating elements in series with the transducer temperature control circuitry, or (d) connecting the first and second heating elements in parallel with the transducer temperature control circuitry.

Multi-temperature heater for use with pressure transducers

A compensated sensor includes a sensor, a relatively fast feedthrough path, and a relatively slow compensation path. The relatively fast feedthrough path includes a summer and output circuitry, such as a summing amplifier. The relatively slow compensation path includes circuitry that produces one or more correction factors for such sensor deficiencies as temperature dependency, or nonlinearity effects, for example. These one or more correction factors are fed to the summer for summing with the uncompensated sensor output. Additionally, the output of the output circuitry (e.g., summing amplifier), is fed back to the compensation circuitry where it is compared to a compensated sensor output developed by the compensation circuitry. The difference between the compensated sensor signal developed in the compensation circuitry and the output signal fed back to the compensation circuitry is also provided to the summer for summing with the one or more correction factors and the uncompensated sensor output.

Apparatus and method for compensated sensor output

A capacitive pressure transducer including a heater shell, a capacitive pressure sensor, an electronics assembly and a thermal barrier is presented. The sensor and the electronics assembly are disposed in the heater shell. The thermal barrier is also disposed in the heater shell and is disposed between the sensor and electronics assembly.

Pressure transducer assembly with thermal shield

A method is disclosed for providing transient temperature compensation in a pressure transducer. The transducer includes a capacitive pressure sensor, the pressure sensor including a diaphragm, at least part of the diaphragm moving in response to changes in a pressure. The transducer may further include an electronic circuit which generates an uncompensated output signal representative of the pressure. The disclosed method generates a compensated output signal according to a function of the uncompensated output signal and a difference between a temperature of the pressure sensor and a temperature of the ambient environment.

Pressure transducer with compensation for thermal transients

A capacitive pressure sensor includes a chamber coupled to a region whose pressure is to be determined. The sensor includes a conductive flexible diaphragm and a pair of electrodes, each defining a capacitance with the diaphragm. Variations in pressure in the chamber cause deflection of the diaphragm which in turn causes variation in the capacitances. A processing circuit applies an excitation signal to the capacitances and couples the capacitances to inductive elements. A current through the inductive elements is detected to determine the difference in the sensor capacitances and, therefore, the deflection of the diaphragm and the pressure in the chamber.

Capacitive pressure sensing method and apparatus avoiding interelectrode

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South Natick, MA, United States of America

Leonid Mindlin