US4228393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moisture meter
Assignee: Brown and Williamson Holdings Inc
•
Filing: 1978-08-14
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Granted: 1980-10-14
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Expires: 1998-08-14
Abstract
Abstract A meter for measuring the dielectric constant of a predetermined amount of tobacco to determine the moisture content. The meter includes a sample holder with a capacitor to retain a predetermined amount of tobacco between the plates of the capacitor. A stable reference frequency, a phase comparator, and a voltage controlled oscillator are interconnected to form a phase-locked loop frequency controller. The voltage controlled oscillator is connected to the capacitor to detect a change in capacitance causing the oscillator to attempt to change frequency which in turn causes the output of the phase comparator to change and hold the circuit to the reference frequency. The phase comparator output is proportional to the moisture content of the tobacco. An indicator is responsive to the electrical output of the phase comparator to indicate the moisture content.
Inventors
- 👤 James E. Pile
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:11
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2617; G01R27/2623
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
144 words
A meter for measuring the dielectric constant of a predetermined amount of material constituting a sample to determine the moisture content thereof comprising: a capacitor having means to receive the sample, a stable reference frequency means, a phase comparator, and a voltage controlled oscillator interconnected to form a phase-locked loop frequency controller; the voltage controlled oscillator being connected to the capacitor to detect a change in capacitance causing the voltage controlled oscillator to change frequency which due to the phase-locked loop condition causes the ouput of the phase comparator to change and maintain the frequency of the voltage controlled oscillator at the frequency of the stable reference frequency means; the phase comparator output being proportional to the moisture content of the material; and, indicating means connected to the phase comparator and responsive to the output of the phase comparator to indicate the moisture content.
Claim 2
Dependent Claim
144 words
A meter for measuring the dielectric constant of a predetermined amount of material constituting a sample to determine the moisture content thereof comprising: a capacitor having means to receive the sample, a stable reference frequency means, a phase comparator, and a voltage controlled oscillator interconnected to form a phase-locked loop frequency controller; the voltage controlled oscillator being connected to the capacitor to detect a change in capacitance causing the voltage controlled oscillator to change frequency which due to the phase-locked loop condition causes the ouput of the phase comparator to change and maintain the frequency of the voltage controlled oscillator at the frequency of the stable reference frequency means; the phase comparator output being proportional to the moisture content of the material; and, indicating means connected to the phase comparator and responsive to the output of the phase comparator to indicate the moisture content.
Claim 3
Dependent Claim
15 words
The meter in accordance with claim 1 wherein the predetermined amount of material is tobacco.
Claim 4
Dependent Claim
129 words
The meter in accordance with claim 1 wherein the phase-locked loop condition is produced by means for determining the frequency of the voltage control oscillator near enough to the reference frequency that the phase comparator output forces the voltage controlled oscillator to lock onto the reference frequency thus causing the voltage controlled oscillator to remain at the reference frequency, the means for determining the frequency of the voltage controlled oscillator being designed to control the voltage controlled oscillator if the voltage input to the voltage controlled oscillator from the phase comparator is at a preselected point above zero thereby producing locked conditions whereby an attempt to change the voltage controlled oscillator will change the output of the phase comparator and maintain the voltage controlled oscillator at the reference frequency.
Claim 5
Dependent Claim
24 words
The meter in accordance with claim 3 wherein the capacitor is part of the means to determine the frequency of the voltage controlled oscillator.
Claim 6
Dependent Claim
25 words
The meter in accordance with claim 4 wherein the means for determining the frequency of the voltage controlled oscillator is a resistor and capacitor network.
Claim 7
Dependent Claim
22 words
The meter in accordance with claim 1 wherein the capacitor is a sample holding means to retain a predetermined amount of material.
Claim 8
Dependent Claim
21 words
The meter in accordance with claim 6 wherein the capacitor has a pair of spaced plates to receive a sample therebetween.
Claim 9
Dependent Claim
20 words
The meter in accordance with claim 1 wherein the capacitor is a fringing capacitor disposed above the flow of material.
Claim 10
Dependent Claim
21 words
The meter in accordance with claim 1 wherein the capacitor is a fringing capacitor disposed beneath the flow of material thereabove.
References Cited (Backward Citations)
US3443220A
Cited
US3397364A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |