Apparatus for monitoring impurities in a gas stream
US5339675A · kind A · utility
29Cited by
12References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1992 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Oct 8, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0426
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device is provided comprising a piezoelectric material and at least one coating reactive with trace quantities of oxygen and/or water in reactive and inert gases. The piezoelectric material is bonded to a conductor for delivering an alternating electric current and to a conductor for transmitting resonant vibration frequency of the crystal. The reactive coating has an effective thickness which provides a serviceable life for the coating while not being so thick as to prevent vibration of the piezoelectric material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.