Apparatus and method for measuring pressures and indicating leaks with optical analysis
US4270091A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 17, 1978 |
| Grant date | May 26, 1981 |
| Priority date | — |
| Expiry date | Nov 17, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L21/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A partial pressure gauge utilizes an efficient electron collision excitation source yielding de-excitation radiation characteristic of residual gases. The intensity of a given spectral line is proportional to the partial pressure of the gas having such spectral line, and the current drawn from the excitation source provides a measure of the total pressure. A calibration technique based upon comparing the emitted light intensity with the ion currents associated with the excitation process yields an accurate measure of the relative partial pressure. Use of a filter to selectively pass radiation from a known constituent in known proportion in ambient gas provides an indication of the presence of a leak without the need for probing with a test gas. Provision for passing an evaporant stream through the excitation region permits accurate monitoring of the evaporant flux from which deposition rate is determined. In combination with techniques for achieving high differential sensitivity to fluctuations in light output from a selected spectral line, a novel leak detector is achieved. In combination with an optically dispersive element a residual gas analyzer is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.