Patent US3686606A successfully refreshed from Google Patents.
US3686606A
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Electrical humidity sensing element
Assignee: Johnson Controls International Inc
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Filing: 1970-08-24
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Granted: 1972-08-22
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Expires: 1990-08-24
Abstract
Abstract A varying dimension electrical humidity sensing element for use in a humidity control and/or humidity indication system. The element includes a moisture sensitive material, which is capable of varying its dimension with changes in relative humidity, and a series of interconnected, electrically conductive particles of hydrophobic carbon are distributed within the moisture sensitive material. Dimensional changes in the moisture sensitive material caused by variations in moisture conditions act to vary the electrical resistance of the element and provide an indication of the relative humidity.
Inventors
- 👤 Paul E Thoma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:46
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/121; G01N19/00; G01N19/10
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
65 words
In an electrical variable dimension humidity sensing element, a material sensitive to changes in the moisture content of the atmosphere and capable of varying its dimension in response to said variations in moisture content, and a plurality of interconnected electrically conductive hydrophobic particles of carbon dispersed within a substantial portion of said material and disposed in sufficient contact to effect a measurement of variable resistance.
Claim 2
Dependent Claim
65 words
In an electrical variable dimension humidity sensing element, a material sensitive to changes in the moisture content of the atmosphere and capable of varying its dimension in response to said variations in moisture content, and a plurality of interconnected electrically conductive hydrophobic particles of carbon dispersed within a substantial portion of said material and disposed in sufficient contact to effect a measurement of variable resistance.
Claim 3
Dependent Claim
34 words
The element of claim 1, wherein said carbon particles adsorb and/or absorb less than 4 percent by weight of water at 78* F when subjected to changes from 0 to 90 percent relative humidity.
Claim 4
Dependent Claim
32 words
The element of claim 1, wherein said carbon particles have a volatile content as chemisorbed surface oxygen of less than 6.0 X 10 5 gram per square meter of carbon surface area.
Claim 5
Dependent Claim
13 words
The element of claim 1, wherein said carbon particles are fused agglomerated clusters.
Claim 6
Dependent Claim
13 words
The element of claim 4, wherein the agglomerated clusters have a chain-like structure.
Claim 7
Dependent Claim
30 words
The element of claim 5, wherein the chain-like agglomerated clusters have an average largest dimension at least three times greater than the average smallest dimension of the chain-like agglomerated structure.
Claim 8
Dependent Claim
26 words
The element of claim 1, wherein the individual carbon particles have an average size in the range of 1 m Mu to 100 m Mu .
Claim 9
Dependent Claim
13 words
The element of claim 1, wherein the carbon particles have an amorphous structure.
Claim 10
Dependent Claim
13 words
The element of claim 1, wherein the carbon particles have a graphitized structure.
Claim 11
Dependent Claim
27 words
The element of claim 1, wherein said material will show a dimensional increase greater than 0.5 percent with a change of 0 to 100 percent relative humidity.
Claim 12
Dependent Claim
18 words
The element of claim 1, wherein said particles comprise up to 50 percent by weight of said material.
Claim 13
Dependent Claim
19 words
The element of claim 1, and including a hydrolyzed surface layer disposed on the outer surface of said material.
Claim 14
Dependent Claim
99 words
An electrical variable dimension humidity sensing element, comprising a core formed of a material sensitive to moisture and characterized by the ability to respond in the form of dimensional changes to changes in relative humidity, and a plurality of interconnected electrically conductive hydrophobic particles of carbon embedded and dispersed within a substantial portion of said core and disposed in sufficient contact to effect a measurement of variable resistance, and an outer layer bonded to a substantial surface portion of the core and characterized by the ability to respond in the form of dimensional changes to changes in relative humidity.
Claim 15
Dependent Claim
99 words
An electrical variable dimension humidity sensing element, comprising a core formed of a material sensitive to moisture and characterized by the ability to respond in the form of dimensional changes to changes in relative humidity, and a plurality of interconnected electrically conductive hydrophobic particles of carbon embedded and dispersed within a substantial portion of said core and disposed in sufficient contact to effect a measurement of variable resistance, and an outer layer bonded to a substantial surface portion of the core and characterized by the ability to respond in the form of dimensional changes to changes in relative humidity.
Claim 16
Dependent Claim
34 words
The element of claim 13, wherein said carbon particles adsorb and/or absorb less than 4 percent by weight of water at 78* F when subjected to changes from 0 to 90 percent relative humidity.
Claim 17
Dependent Claim
32 words
The element of claim 13, wherein said carbon particles have a volatile content as chemisorbed surface oxygen of less than 6.0 X 10 5 gram per square meter of carbon surface area.
Claim 18
Dependent Claim
13 words
The element of claim 13, wheRein said carbon particles are fused agglomerated clusters.
Claim 19
Dependent Claim
17 words
The element of claim 13, wherein the outer layer has a greater moisture sensitivity than the core.
Claim 20
Dependent Claim
29 words
The element of claim 13, wherein the outer layer will show a dimensional increase of at least 0.50 percent with a change from 0 to 100 percent relative humidity.
Claim 21
Dependent Claim
20 words
The element of claim 13, and including a hydrolyzed surface layer bonded to the outer surface of said outer layer.
Claim 22
Dependent Claim
22 words
The element of claim 13, wherein said core has a moisture sensitivity equal to or greater than that of the outer layer.
Claim 23
Dependent Claim
102 words
An electrical apparatus, comprising an electrical circuit, a humidity sensing element including a material sensitive to changes in the moisture content of the atmosphere and capable of varying its dimension in response to said variations in moisture content, a plurality of interconnected electrically conductive hydrophobic particles of carbon dispersed within a substantial portion of said material and disposed in sufficient contact to effect a measurement of variable resistance, and means for connecting spaced portions of said material in said electrical circuit, whereby variations in moisture conditions cause a rearrangement of the hydrophobic carbon particles to vary the current flow through the circuit.
Claim 24
Dependent Claim
102 words
An electrical apparatus, comprising an electrical circuit, a humidity sensing element including a material sensitive to changes in the moisture content of the atmosphere and capable of varying its dimension in response to said variations in moisture content, a plurality of interconnected electrically conductive hydrophobic particles of carbon dispersed within a substantial portion of said material and disposed in sufficient contact to effect a measurement of variable resistance, and means for connecting spaced portions of said material in said electrical circuit, whereby variations in moisture conditions cause a rearrangement of the hydrophobic carbon particles to vary the current flow through the circuit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |