US3639841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic energy dosimeter
Assignee: Individual
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Filing: 1970-01-16
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Granted: 1972-02-01
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Expires: 1990-01-16
Abstract
Abstract Miniaturized dosimeter apparatus monitors the field density of radiated pulsed electromagnetic energy. An elongate cylindrical coil is used as a pickup and is positioned so that one-half of the coil protrudes from a small metallic case for the apparatus, providing uniform response substantially over a spherical angle of at least 180*. Means is interconnected with the coil for producing a periodic waveform having an average magnitude varying as a function of the field density of the radiated energy and having a period inversely proportional to the pulse repetition frequency of the energy. Means is responsive to this periodic waveform for providing a readily perceptible indication of the average magnitude of the periodic waveform whereby the field density of the radiated energy, and thereby the relative human thermogenic dosage thereof, is readily monitored.
Inventors
- 👤 Alfred W Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:47
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/08; G01R29/0807; G01R29/0814; G01R29/0857
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
159 words
Dosimeter apparatus for monitoring the field density of radiated pulsed electromagnetic energy comprising: a pickup responsive to said radiated energy, and constituted by an elongate cylindrical coil having a plurality of turns of wire spaced uniformly along the length thereof; means for electromagnetically shielding approximately half said length of the coil beginning at one end thereof, whereby said coil is uniformly responsive to the radiated energy substantially over a spherical angle of at least 180*; means interconnected with said coil in an untuned circuit for producing a periodic waveform having an average magnitude which varies as a function of the field density of said radiated energy and having a period which is inversely proportional to the pulse repetition frequency thereof; means responsive to said periodic waveform for providing a readily perceptible indication of the average magnitude of said periodic waveform whereby the field density of said radiated energy, and thereby the relative human thermogenic dosage thereof, is readily monitored.
Claim 2
Dependent Claim
159 words
Dosimeter apparatus for monitoring the field density of radiated pulsed electromagnetic energy comprising: a pickup responsive to said radiated energy, and constituted by an elongate cylindrical coil having a plurality of turns of wire spaced uniformly along the length thereof; means for electromagnetically shielding approximately half said length of the coil beginning at one end thereof, whereby said coil is uniformly responsive to the radiated energy substantially over a spherical angle of at least 180*; means interconnected with said coil in an untuned circuit for producing a periodic waveform having an average magnitude which varies as a function of the field density of said radiated energy and having a period which is inversely proportional to the pulse repetition frequency thereof; means responsive to said periodic waveform for providing a readily perceptible indication of the average magnitude of said periodic waveform whereby the field density of said radiated energy, and thereby the relative human thermogenic dosage thereof, is readily monitored.
Claim 3
Dependent Claim
39 words
Dosimeter apparatus as set forth in claim 1 wherein said means for electromagnetically shielding a portion of said coil comprises a metallic enclosure for said apparatus and substantially exactly half the length of said coil protrudes from said enclosure.
Claim 4
Dependent Claim
34 words
Dosimeter apparatus as set forth in claim 1 wherein said means for producing a periodic waveform comprises means for integrating said radiated energy whereby said periodic waveform varies substantially according to a sawtooth characteristic.
Claim 5
Dependent Claim
49 words
Dosimeter apparatus as set forth in claim 3 wherein said means responsive to said periodic signal comprises a first linear differential amplifier for amplifying said periodic waveform and means for integrating said amplified waveform to produce a voltage varying substantially according to the field density of said radiated energy.
Claim 6
Dependent Claim
29 words
Dosimeter apparatus as set forth in claim 4 further comprising a meter for indicating said voltage to provide a visual indication of the field density of said radiated energy.
Claim 7
Dependent Claim
29 words
Dosimeter apparatus as set forth in claim 5 wherein said meter is calibrated to a predetermined maximum field density of said radiated energy which is safe for human exposure.
Claim 8
Dependent Claim
44 words
Dosimeter apparatus as set forth in claim 3 wherein said means responsive to said periodic waveform comprises a second linear differential amplifier for amplifying said periodic waveform to produce an audio signal providing for auditory indication of the field density of said radiated energy.
Claim 9
Dependent Claim
29 words
Dosimeter apparatus as set forth in claim 7 further comprising a transducer interconnected with said second amplifier and giving auditory indication of the field density of said radiated energy.
Claim 10
Dependent Claim
41 words
Dosimeter apparatus as set forth in claim 2 further comprising a gas-filled cold cathode glow-discharge device protruding from said enclosure for providing a glow indication when said field density reaches a predetermined value causing ionization of the gas in said device.
Claim 11
Dependent Claim
16 words
Dosimeter apparatus as set forth in claim 9 wherein said glow-discharge device comprises a neon bulb.
Claim 12
Dependent Claim
50 words
Dosimeter apparatus as set forth in claim 1 further comprising a notch filter interconnection said pickup and said means for producing a periodic signal, said filter being adapted to prevent electromagnetic fields substantially at a preselected frequency picked up by said pickup from being supplied to the last said means.
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |