US5069069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture-sensitive element for moisture sensors
Assignee: Azbil Corp
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Filing: 1990-04-26
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Granted: 1991-12-03
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Expires: 2010-04-26
Abstract
Abstract A moisture-sensitive element comprising a moisture-sensitive film which consists of a polymer (such as a polymer in which polyethersulfon is a principal component) whose water sorption amount is between 10 and 40 mg/g at a temperature of 30° C. and a relative humidity of 90% RH. The temperature-sensitive element has a low temperature dependency, a small hysteresis and a quick response and accordingly can be employed in a wide range of temperature as well as in a severe condition such as high humidity, high temperature, cyclically fluctuating humidity, low humidity, moisture condensation, water dipping and so on.
Inventors
- 👤 Tetsuya Miyagishi
- 👤 Toru Abe
- 👤 Takaaki Kuroiwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:19
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01N27/225
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
72 words
A sensor for moisture in an atmosphere comprising in combination; a film composed principally of a polymer with a water sorption capacity in a range between 10 and 40 milligrams of water per gram of polymer at a temperature of 30° C. and a relative humidity of 90% RH, means for sensing a change in a characteristic of said film which change is a function of the moisture adsorbed by said film.
Claim 2
Dependent Claim
72 words
A sensor for moisture in an atmosphere comprising in combination; a film composed principally of a polymer with a water sorption capacity in a range between 10 and 40 milligrams of water per gram of polymer at a temperature of 30° C. and a relative humidity of 90% RH, means for sensing a change in a characteristic of said film which change is a function of the moisture adsorbed by said film.
Claim 3
Dependent Claim
22 words
A sensor for moisture in an atmosphere as recited in claim 1 wherein said characteristic is the electrical capacitance of said film.
Claim 4
Dependent Claim
25 words
A sensor for moisture in an atmosphere as recited in claim 1 wherein said polymer is selected form the group consisting of polyethersulfon and polysulfon.
Claim 5
Dependent Claim
28 words
A sensor for moisture in an atmosphere as recited in claim 3, wherein said polymer is polyethersulfon annealed at a temperature ranging between 160° C. and 240° C.
Claim 6
Dependent Claim
28 words
A sensor for moisture in an atmosphere as recited in claim 3 wherein said polymer is polysulfon annealed at a temperature ranging between 140° C. and 200° C.
Claim 7
Dependent Claim
32 words
A sensor for moisture in an atmosphere as recited in claim 1 wherein said polymer has a glass transition temperature greater than 100° C. and a melting point greater than 150° C.
Claim 8
Dependent Claim
26 words
A sensor for moisture in an atmosphere as recited in claim 1 wherein said polymer has a volume resistivity greater than 10 14 Ohms per centimeter.
Claim 9
Dependent Claim
26 words
A sensor for moisture in an atmosphere as recited in claim 1 wherein said polymer has a dielectric breakdown strength greater than 14 kilovolts per millimeter.
Claim 10
Dependent Claim
34 words
A sensor for moisture in an atmosphere as recited in claim 1 wherein said polymer has a thermal deflection temperature under load above 120° C. and a resistance to heat temperature above 100° C.
Claim 11
Dependent Claim
100 words
A sensor for sensing moisture in an atmosphere comprising in combination: a first conductor; a film disposed on said first conductor composed principally of a polymer with a water sorption capacity in a range between 10 and 40 milligrams of water per gram of polymer at a temperature of 30° C. and a relative humidity of 90% RH; a second conductor disposed on said film; and means to couple said first and second conductors to a source of electrical energy whereby the moisture in said atmosphere can be sensed by detecting a change in an electrical property of said film.
Claim 12
Dependent Claim
100 words
A sensor for sensing moisture in an atmosphere comprising in combination: a first conductor; a film disposed on said first conductor composed principally of a polymer with a water sorption capacity in a range between 10 and 40 milligrams of water per gram of polymer at a temperature of 30° C. and a relative humidity of 90% RH; a second conductor disposed on said film; and means to couple said first and second conductors to a source of electrical energy whereby the moisture in said atmosphere can be sensed by detecting a change in an electrical property of said film.
Claim 13
Dependent Claim
24 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said electrical property is an electrical capacitance of said film.
Claim 14
Dependent Claim
24 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said electrical property is an electrical impedance of said film.
Claim 15
Dependent Claim
26 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said polymer is selected from the group consisting of polyethersulfon and polysulfon.
Claim 16
Dependent Claim
29 words
A sensor for sensing moisture in an atmosphere as recited in claim 13 wherein said polymer is polyethersulfon annealed at a temperature ranging between 160° C. and 240° C.
Claim 17
Dependent Claim
29 words
A sensor for sensing moisture in an atmosphere as recited in claim 13 wherein said polymer is polysulfon annealed at a temperature ranging between 140° C. and 200° C.
Claim 18
Dependent Claim
33 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said polymer has a glass transition temperature greater than 100° C. and a melting point greater than 150° C.
Claim 19
Dependent Claim
27 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said polymer has a volume resistivity greater than 10 14 Ohms per centimeter.
Claim 20
Dependent Claim
27 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said polymer has a dielectric breakdown strength greater than 14 kilovolts per millimeter.
Claim 21
Dependent Claim
35 words
A sensor for sensing moisture in an atmosphere as recited in claim 10 wherein said polymer has a thermal deflection temperature under load above 120° C. and a resistance to heat temperature above 100° C.
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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) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |