US3812419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic field mill
Assignee: United States Department of the Army
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Filing: 1973-03-05
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Granted: 1974-05-21
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Expires: 1993-03-05
Abstract
Abstract This invention relates to electrostatic fields and particularly to instruments for measuring the strength of electrostatic fields. More particularly this disclosure describes a device using electronic means for modulating the strength of an electrostatic field in front of a sensing electrode to simulate the field-mill effect and produce alternating voltage components resulting in an average voltage shift proportional to the field strength at that point. This average voltage shift is amplified and applied to a suitable means to indicate the relative field strength.
Inventors
- 👤 H Kaunzinger
- 👤 R Buser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:52
CPC Classifications
G; G01; G01R; G01R5/00; G01R5/28
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
139 words
A device for measuring the strength of an electrostatic field near a surface area of a body facing in a particular direction comprising: a sensing probe fixedly positioned near said surface area of said said body and having a sensing surface area facing as said surface area of said body; a conductive grid means positioned in front of said sensing surface of said probe; a conductive shielding enclosure conductively connected to the periphery of said grid means and enclosing said probe; modulating means connected between said shielding enclosure and said grid means, in common, and to said body to modulate the electrostatic field strengths sensed by said probe; means connected to said probe for amplifying signals corresponding to modulated electrostatic field strengths at said probe; and indicator means connected between the output of said amplifying means and said body.
Claim 2
Independent Claim
139 words
A device for measuring the strength of an electrostatic field near a surface area of a body facing in a particular direction comprising: a sensing probe fixedly positioned near said surface area of said said body and having a sensing surface area facing as said surface area of said body; a conductive grid means positioned in front of said sensing surface of said probe; a conductive shielding enclosure conductively connected to the periphery of said grid means and enclosing said probe; modulating means connected between said shielding enclosure and said grid means, in common, and to said body to modulate the electrostatic field strengths sensed by said probe; means connected to said probe for amplifying signals corresponding to modulated electrostatic field strengths at said probe; and indicator means connected between the output of said amplifying means and said body.
Claim 3
Dependent Claim
13 words
A device as in claim 1 wherein said sensing surface is substantially flat.
Claim 4
Dependent Claim
21 words
A device as in claim 1 wherein said sensing surface is substantially coplanar with the nearby surface area of said body.
Claim 5
Dependent Claim
22 words
A device as in claim 3 wherein said shielding enclosure is positioned in an opening in said surface area of said body.
Claim 6
Dependent Claim
18 words
A device as in claim 1 wherein said means for amplifying the modulated signals comprises an electrometer amplifier.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |