US4584522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital direct reading grain moisture tester
Assignee: ELECTREX Inc
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Filing: 1983-08-11
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Granted: 1986-04-22
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Expires: 2003-08-11
Abstract
Abstract A direct measuring digital grain moisture meter comprises a light weight power supply, an oscillator, a two plate capacitor having a receptacle admitting a grain sample acting as the capacitor dielectric, and a detector/display measuring the dielectric constant and hence moisture content of the grain sample and displaying a numeric representation the moisture content of the grain. The meter provides a direct reading of grain moisture content requiring no further mathematical manipulation by the user or external temperature compensation.
Inventors
- 👤 Marco E. Varela
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:41
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/02; G01N33/10; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2605
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
155 words
Apparatus for directy measuring the moisture content of particulate material comprising a casing having a top well provided with an opening to a receptacle adapted to receive said particulate material with parallel electrode plates defining two opposite sides of said receptacle and forming a capacitor, an oscillator means having an output with a charging half cycle and a discharging half cycle, detector means determining the capacitance between said electrode plates comprising a capacitor charging path having a first given resistance and a diode forward biased in the charging half cycle and reverse biased during the discharging half cycle; a capacitor discharging path having a second given resistance different from said first given resistance and a diode forward biased in the discharging half cycle and reverse biased in the charging half cycle; and, an output voltage proportional to the charge retained on said electrode plate; and means converting said detector output to a visually pereceptable form.
Claim 2
Dependent Claim
155 words
Apparatus for directy measuring the moisture content of particulate material comprising a casing having a top well provided with an opening to a receptacle adapted to receive said particulate material with parallel electrode plates defining two opposite sides of said receptacle and forming a capacitor, an oscillator means having an output with a charging half cycle and a discharging half cycle, detector means determining the capacitance between said electrode plates comprising a capacitor charging path having a first given resistance and a diode forward biased in the charging half cycle and reverse biased during the discharging half cycle; a capacitor discharging path having a second given resistance different from said first given resistance and a diode forward biased in the discharging half cycle and reverse biased in the charging half cycle; and, an output voltage proportional to the charge retained on said electrode plate; and means converting said detector output to a visually pereceptable form.
Claim 3
Dependent Claim
13 words
The apparatus of claim 1 wherein said detector includes a low pass filter.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1 wherein said second given resistance is higher than said first given resistance.
Claim 5
Dependent Claim
19 words
The apparatus of claim 1 wherein said coverting means comprises an analog to digital converter driving a digital display.
Claim 6
Dependent Claim
37 words
The apparatus of claim 4 wherein said analog to digital converter includes an offset adjustment circuit such that said digital display shows a number equal to an offset value plus a value proportional to said detector output.
Claim 7
Dependent Claim
32 words
The apparatus of claim 5 wherein said offset adjustment circuit includes a temperature sensistive element disposed in said receptacle whereby said offset value is dependent on the temperature of said particulate material.
Claim 8
Dependent Claim
159 words
Apparatus for directly measuring the moisture content of particulate material comprising a casing having a top wall provided with an opening to a receptacle adapted to receive said particulate material with parallel electrode plates forming a capacitor defining two opposite sides of said receptacle; an oscillator means having an output with a charging half cycle and a discharging half cycle; means applying said oscillator output to said electrode plates; detector means comprising a charging path for said capacitor having a low resistance and a diode forward biased in the charging half cycle and reverse biased in the discharging half cycle, a discharging path for said capacitor having a high resistance and a diode forward biased in the discharging half cycle and reverse biased in the charging half cycle and an output voltage proportional to the charge retained on said electrode plates; and, an analog to digital converter producing a visually perceptable digital representation dependent on said detector output voltage.
Claim 9
Dependent Claim
159 words
Apparatus for directly measuring the moisture content of particulate material comprising a casing having a top wall provided with an opening to a receptacle adapted to receive said particulate material with parallel electrode plates forming a capacitor defining two opposite sides of said receptacle; an oscillator means having an output with a charging half cycle and a discharging half cycle; means applying said oscillator output to said electrode plates; detector means comprising a charging path for said capacitor having a low resistance and a diode forward biased in the charging half cycle and reverse biased in the discharging half cycle, a discharging path for said capacitor having a high resistance and a diode forward biased in the discharging half cycle and reverse biased in the charging half cycle and an output voltage proportional to the charge retained on said electrode plates; and, an analog to digital converter producing a visually perceptable digital representation dependent on said detector output voltage.
Claim 10
Dependent Claim
37 words
The apparatus of claim 7 wherein said analog to digital converter includes an offset adjustment circuit such that said digital display shows a number equal to an offset value plus a value proportional to said detector output.
Claim 11
Dependent Claim
32 words
The apparatus of claim 8 wherein said offset adjustment circuit includes a temperature sensistive element disposed in said receptacle whereby said offset value is dependent on the temperature of said particulate material.
Claim 12
Independent Claim
130 words
A method of measuring the moisture content of particulate material comprising the following steps: placing a sample of said particulate material in a receptacle having two opposite sides forming the plates of a capacitor, applying an oscillating current to said capacitor, providing a charging path having a first given resistance and a discharging path having a second given resistance different from said first given resistance for said capacitor, measuring the average charge retained on said capacitor over at least several oscillations of said oscillating current and providing a charge signal representative of said average charge, creating an offset signal dependent on the temperature of said particulate material, adding said charge signal to said offset signal to produce a total signal, and providing a visually perceptable representation of said total signal.
Claim 13
Independent Claim
130 words
A method of measuring the moisture content of particulate material comprising the following steps: placing a sample of said particulate material in a receptacle having two opposite sides forming the plates of a capacitor, applying an oscillating current to said capacitor, providing a charging path having a first given resistance and a discharging path having a second given resistance different from said first given resistance for said capacitor, measuring the average charge retained on said capacitor over at least several oscillations of said oscillating current and providing a charge signal representative of said average charge, creating an offset signal dependent on the temperature of said particulate material, adding said charge signal to said offset signal to produce a total signal, and providing a visually perceptable representation of said total signal.
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) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |