Wide-range combination vacuum gauge
AssigneeBrooks Automation, Inc.
InventorsPaul M. Rutt, Michael D. Borenstein
Life of this patent
Estimating the term…
Abstract
A combination vacuum gauge provides simultaneous absolute and differential pressure measurements over a wide range of pressures ranging from atmospheric pressures to ultrahigh vacuum by processing the readings from an absolute high vacuum gauge (e.g., an ionization gauge and/or a heat-loss sensor), a differential low vacuum gauge providing a differential relative to ambient pressure (e.g., a diaphragm sensor), and a barometric absolute pressure sensor exposed to the ambient atmosphere outside the measurement region. The barometric absolute pressure sensor reading is used to convert the differential vacuum gauge reading from uncalibrated differential pressure to calibrated absolute pressure.
Claims17
An apparatus for measuring gas pressure in a measurement region comprising:
- an absolute high vacuum gauge;
- a differential low vacuum gauge providing a differential relative to ambient pressure;
- a barometric absolute pressure sensor, the barometric absolute pressure sensor being exposed only to the ambient atmosphere outside the measurement region;
- and
- a processor coupled to the absolute high vacuum gauge, the differential low vacuum gauge, and the barometric absolute pressure gauge, the processor providing absolute gas pressure indications in the ranges of high and low vacuum and differential gas pressure indications at low vacuum.
A method for measuring gas pressure in a measurement region comprising the step of:
- providing an absolute high vacuum gauge;
- providing a differential low vacuum gauge providing a differential relative to ambient pressure;
- providing a barometric absolute pressure sensor, the barometric absolute pressure sensor being exposed only to the ambient atmosphere outside the measurement region;
- and
- providing absolute gas pressure indications in the ranges of high and low vacuum and differential gas pressure indications at low vacuum based on data output from the absolute high vacuum gauge, the differential low vacuum gauge, and the barometric absolute pressure sensor.
An apparatus for measuring gas pressure in a measurement region comprising:
- an absolute high vacuum gauge;
- a differential low vacuum gauge providing a differential relative to ambient pressure;
- a barometric absolute pressure sensor, the barometric absolute pressure sensor being exposed only to the ambient atmosphere outside the measurement region;
- and
- means for providing absolute gas pressure indications in the ranges of high and low vacuum and differential gas pressure indications at low vacuum based on data output from the absolute high vacuum gauge, the differential low vacuum gauge, and the barometric absolute pressure sensor.
Dependencies are inferred from the claim text.