US5339675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for monitoring impurities in a gas stream
Assignee: Entegris Inc
•
Filing: 1992-10-08
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Granted: 1994-08-23
•
Expires: 2012-10-08
Abstract
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.
Inventors
- 👤 Anthony J. DiLeo
- 👤 James T. Snow
- 👤 Daniel A. Cote
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:01
CPC Classifications
G; G01; G01H; G01H11/00; G01H11/06; G01H11/08; G01N; G01N29/00; G01N29/02; G01N29/036; G01N29/022; G01N2291/00; G01N2291/01; G01N2291/014; G01N2291/02; G01N2291/025; G01N2291/0256; G01N2291/028; G01N2291/02809; G01N2291/02845; G01N2291/04; G01N2291/042; G01N2291/0423; G01N2291/0426
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
135 words
A sensing device for measuring a first composition selected from the group consisting of oxygen, water and mixtures thereof in a stream of purified gases which comprises: a piezoelectric material having a surface with an effective mass of a coating applied to said surface of said piezoelectric material, said coating formed of a second composition selected from the group consisting of a pure metal, a metal hydride and mixtures thereof; said second composition being reactive with said first composition to form a product selected from the group consisting of an oxide, a hydroxide and mixtures thereof, said coating having a mass which permits said piezoelectric material to vibrate in response to electrical current, means for applying an alternating electrical current to said piezoelectric material and means for measuring frequency of vibration of said piezoelectric material.
Claim 2
Dependent Claim
135 words
A sensing device for measuring a first composition selected from the group consisting of oxygen, water and mixtures thereof in a stream of purified gases which comprises: a piezoelectric material having a surface with an effective mass of a coating applied to said surface of said piezoelectric material, said coating formed of a second composition selected from the group consisting of a pure metal, a metal hydride and mixtures thereof; said second composition being reactive with said first composition to form a product selected from the group consisting of an oxide, a hydroxide and mixtures thereof, said coating having a mass which permits said piezoelectric material to vibrate in response to electrical current, means for applying an alternating electrical current to said piezoelectric material and means for measuring frequency of vibration of said piezoelectric material.
Claim 3
Dependent Claim
15 words
The device of claim 1 wherein said material has said coating on two opposing surfaces.
Claim 4
Dependent Claim
11 words
The device of claim 1 wherein said piezoelectric material is quartz.
Claim 5
Dependent Claim
11 words
The device of claim 2 wherein said piezoelectric material is quartz.
Claim 6
Dependent Claim
10 words
The device of claim 1 wherein said coating is barium.
Claim 7
Dependent Claim
10 words
The device of claim 2 wherein said coating is barium.
Claim 8
Dependent Claim
10 words
The device of claim 3 wherein said coating is barium.
Claim 9
Dependent Claim
10 words
The device of claim 4 wherein said coating is barium.
Claim 10
Dependent Claim
11 words
The device of claim 1 wherein said coating is magnesium hydride.
Claim 11
Dependent Claim
11 words
The device of claim 2 wherein said coating is magnesium hydride.
Claim 12
Dependent Claim
11 words
The device of claim 3 wherein said coating is magnesium hydride.
Claim 13
Dependent Claim
11 words
The device of claim 4 wherein said coating is magnesium hydride.
Claim 14
Dependent Claim
11 words
The device of claim 1 wherein said coating is lithium hydride.
Claim 15
Dependent Claim
11 words
The device of claim 2 wherein said coating is lithium hydride.
Claim 16
Dependent Claim
11 words
The device of claim 3 wherein said coating is lithium hydride.
Claim 17
Dependent Claim
11 words
The device of claim 4 wherein said coating is lithium hydride.
Claim 18
Dependent Claim
10 words
The device of claim 1 wherein said coating is lithium.
Claim 19
Dependent Claim
10 words
The device of claim 2 wherein said coating is lithium.
Claim 20
Dependent Claim
10 words
The device of claim 3 wherein said coating is lithium.
Claim 21
Dependent Claim
10 words
The device of claim 4 wherein said coating is lithium.
Claim 22
Dependent Claim
12 words
The device of claim 1 wherein said piezoelectric material is poly(vinylidene fluoride).
Claim 23
Dependent Claim
13 words
The device of claim 2 wherein said piezoelectric material is poly (vinylidene fluoride).
Claim 24
Dependent Claim
15 words
The device of claim 1 wherein said coating includes a protective material comprising poly(vinylidene fluoride).
Claim 25
Dependent Claim
14 words
The device of claim 1 wherein said coating includes a protective material comprising polytetrafluoroethylene.
Claim 26
Dependent Claim
15 words
The device of claim 2 wherein said coating includes a protective material comprising poly(vinylidene fluoride).
Claim 27
Dependent Claim
14 words
The device of claim 2 wherein said coating includes a protective material comprising polytetrafluoroethylene.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-22 | 1998-02-21 | 1998-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-22 | 2002-02-21 | 2002-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-22 | 2006-02-21 | 2006-08-23 | $7700.00 | Window Closed / Lapsed |