Patent US5477716A successfully refreshed from Google Patents.
US5477716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for monitoring moisture in a gas stream
Assignee: Entegris Inc
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Filing: 1994-07-27
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Granted: 1995-12-26
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Expires: 2014-07-27
Abstract
Abstract A device is provided comprising a piezoelectric material and at least one non-crystalline non-crystalline metal oxide, crystalline-non-zeolite metal oxide and mixtures thereof coating chemically reactive with trace quantities of water in chemically 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 metal oxide 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
- 👤 James T. Snow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:09
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: 15
Claim 1
Independent Claim
94 words
A sensing device for measuring water content in a stream of purified gases which comprises: a piezoelectric material having an effective mass of a non-crystalline metal oxide coating on at least one surface of said sensing device, with said coating formed of a composition chemically reactive with water to form a metal hydroxide product, said coating having a mass which permits said material to vibrate in response to applied alternating 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
94 words
A sensing device for measuring water content in a stream of purified gases which comprises: a piezoelectric material having an effective mass of a non-crystalline metal oxide coating on at least one surface of said sensing device, with said coating formed of a composition chemically reactive with water to form a metal hydroxide product, said coating having a mass which permits said material to vibrate in response to applied alternating 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
11 words
The device of claim 1 wherein said coating is barium oxide.
Claim 7
Dependent Claim
11 words
The device of claim 2 wherein said coating is barium oxide.
Claim 8
Dependent Claim
11 words
The device of claim 3 wherein said coating is barium oxide.
Claim 9
Dependent Claim
11 words
The device of claim 4 wherein said coating is barium oxide.
Claim 10
Dependent Claim
12 words
The device of claim 1 wherein said piezoelectric material is poly(vinylidene fluoride).
Claim 11
Dependent Claim
13 words
The device of claim 2 wherein said piezoelectric material is poly (vinylidene fluoride).
Claim 12
Dependent Claim
26 words
The device of claim 1 wherein said coating includes a layer of protective material between said metal oxide coating and said piezoelectric material comprising poly(vinylidene fluoride).
Claim 13
Independent Claim
25 words
The device of claim I wherein said coating includes a layer of protective material between said metal oxide coating and said piezoelectric material comprising polytetrafluoroethylene.
Claim 14
Dependent Claim
26 words
The device of claim 2 wherein said coating includes a layer of protective material between said metal oxide coating and said piezoelectric material comprising poly(vinylidene fluoride).
Claim 15
Dependent Claim
25 words
The device of claim 2 wherein said coating includes a layer of protective material between said metal oxide coating and said piezoelectric material comprising polytetrafluoroethylene.
References Cited (Backward Citations)
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Cited
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US5212988A
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US5189902A
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US5339675A
Cited
US5364797A
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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) | 1998-12-25 | 1999-06-26 | 1999-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-25 | 2003-06-26 | 2003-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-25 | 2007-06-26 | 2007-12-26 | $7700.00 | Window Closed / Lapsed |