Patent US3684952A successfully refreshed from Google Patents.
US3684952A
Expired / Lapsed
US
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Apparatus for measuring dielectric constant
Assignee: MOISTURE REGISTER CO
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Filing: 1970-04-07
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Granted: 1972-08-15
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Expires: 1990-04-07
Abstract
Abstract A very high frequency oscillator has an antenna as the frequency determining element. The antenna is immersed in a material having a high ionic conductivity, and the shift in the frequency of the oscillator is measured. The frequency shift is indicative of the dielectric constant and moisture content of the material. A dielectric may be interposed between the antenna and the material to reduce the range of frequency shift of the oscillator.
Inventors
- 👤 John W Lundstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:17
CPC Classifications
G; G01; G01N; G01N22/00; G01N22/04; H; H03; H03B; H03B7/00; H03B7/02; H03B7/06; H03B7/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
144 words
Apparatus for providing an indication of moisture content of material having a high ionic conductivity comprising: a conducting plane having a slot therein forming a very high frequency antenna, one side of said conducting plane being enclosed in a conducting cavity to prevent radiation from said slot on that side of said conducting plane; oscillating means having a low negative resistance coupled to said slot in said conducting plane, with said slot forming the frequency determining element for said oscillating means, said oscillating means oscillating in the range between 100 and 300 megahertz; frequency measuring means coupled to said oscillating means for indicating shifts in frequency thereof; said conducting plane being adapted for immersion of the slot therein in material having a high ionic conductivity for causing a shift in the frequency of said oscillating means indicative of the moisture content of the material.
Claim 2
Dependent Claim
144 words
Apparatus for providing an indication of moisture content of material having a high ionic conductivity comprising: a conducting plane having a slot therein forming a very high frequency antenna, one side of said conducting plane being enclosed in a conducting cavity to prevent radiation from said slot on that side of said conducting plane; oscillating means having a low negative resistance coupled to said slot in said conducting plane, with said slot forming the frequency determining element for said oscillating means, said oscillating means oscillating in the range between 100 and 300 megahertz; frequency measuring means coupled to said oscillating means for indicating shifts in frequency thereof; said conducting plane being adapted for immersion of the slot therein in material having a high ionic conductivity for causing a shift in the frequency of said oscillating means indicative of the moisture content of the material.
Claim 3
Independent Claim
90 words
The method of measuring the moisture content of material having a high ionic conductivity with an oscillator having an antenna as the frequency determining element thereof, the method comprising the following steps: adjusting the oscillator to oscillate in the range of between 100 and 300 megahertz; measuring the frequency of the oscillator with the antenna in air; immersing the antenna in material having a high ionic conductivity; measuring the frequency of the oscillator with the antenna immersed in the material; and determining the frequency shift between the two frequency measurements.
Claim 4
Independent Claim
90 words
The method of measuring the moisture content of material having a high ionic conductivity with an oscillator having an antenna as the frequency determining element thereof, the method comprising the following steps: adjusting the oscillator to oscillate in the range of between 100 and 300 megahertz; measuring the frequency of the oscillator with the antenna in air; immersing the antenna in material having a high ionic conductivity; measuring the frequency of the oscillator with the antenna immersed in the material; and determining the frequency shift between the two frequency measurements.
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) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |