US3668674A
Expired / Lapsed
US
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Method and arrangement for testing of visibility measuring arrangements
Assignee: Impulsphysik GmbH
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Filing: 1970-01-30
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Granted: 1972-06-06
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Expires: 1990-01-30
Abstract
Abstract A normal light input of a visibility meter is blocked and a light guide transmits light directly from the transmitter to the receiver. If the signal generated in the receiver as a function of the received test light is outside a given range, a failure alarm is generated. Proper operation of the visibility alarm relay, the supply voltage source, and the light flash generator are also furnished. The visibility measuring arrangement is tested automatically at predetermined time intervals.
Inventors
- 👤 Werner Westendorf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:18
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/538
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
210 words
In a visibility measuring arrangement including transmitting means, transmitting light flashes in a given direction at predetermined intervals, receiving means receiving back-scattered transmitted light flashes and generating a measuring signal as a function of so-received light, an automatic failure detection arrangement comprising, in combination, timing circuit means having a timing circuit input and a timing circuit output; transducing means receiving light flashes from said transmitting means, transforming said light flashes into corresponding electrical signals, and furnishing said electrical signals to said timing circuit input, said timing circuit means furnishing a timing circuit output signal at said timing circuit output when the interval between said electrical signals at said timing circuit input exceeds a first predetermined interval; blocking means for blocking said back-scattered transmitted light from said receiving means during failure detection; means guiding a test quantity of light flashes directLy from said transmitting means to said receiving means while said blocking means is blocking said back-scattered transmitted light flashes from said receiving means, said receiving means generating a test-measuring signal in response to said test quantity of light flashes; and failure signal generating means for generating a failure signal in response to said timing circuit output signal or when said test-measuring signal is less than a first predetermined measuring signal.
Claim 2
Dependent Claim
210 words
In a visibility measuring arrangement including transmitting means, transmitting light flashes in a given direction at predetermined intervals, receiving means receiving back-scattered transmitted light flashes and generating a measuring signal as a function of so-received light, an automatic failure detection arrangement comprising, in combination, timing circuit means having a timing circuit input and a timing circuit output; transducing means receiving light flashes from said transmitting means, transforming said light flashes into corresponding electrical signals, and furnishing said electrical signals to said timing circuit input, said timing circuit means furnishing a timing circuit output signal at said timing circuit output when the interval between said electrical signals at said timing circuit input exceeds a first predetermined interval; blocking means for blocking said back-scattered transmitted light from said receiving means during failure detection; means guiding a test quantity of light flashes directLy from said transmitting means to said receiving means while said blocking means is blocking said back-scattered transmitted light flashes from said receiving means, said receiving means generating a test-measuring signal in response to said test quantity of light flashes; and failure signal generating means for generating a failure signal in response to said timing circuit output signal or when said test-measuring signal is less than a first predetermined measuring signal.
Claim 3
Dependent Claim
63 words
An arrangement as set forth in claim 1 further comprising additional timing circuit means connected with said timing circuit means and having an additional timing circuit output for furnishing an additional timing circuit output signal in the absence of said electrical signals; and wherein said failure signal generating means further generate said failure signal in response to said additional timing circuit output signal.
Claim 4
Dependent Claim
35 words
An arrangement as set forth in claim 1 wherein said timing circuit is further adapted to generate said timing circuit output signal when said electrical signals occur at intervals less than a second predetermined interval.
Claim 5
Dependent Claim
32 words
An arrangement as set forth in claim 1, wherein said failure signal generating means further generate a failure signal when said test measuring signal is greater than a second predetermined measuring signal.
Claim 6
Dependent Claim
106 words
An arrangement as set forth in claim 4, further comprising first comparing means for comparing said test measuring signal to said first predetermined measuring signal, and generating a first comparison signal when said test measuring signal is less than said first predetermined measuring signal; second comparing means for comparing said test measuring signal to said second predetermined measuring signal and generating a second comparison signal when said test measuring signal is greater than said second predetermined measuring signal; and activating means connected to said first and second comparing means, for activating said failure signal generating means in the presence of said first or second comparison signals.
Claim 7
Dependent Claim
145 words
An arrangement as set forth in claim 1, wherein said visibility measuring arrangement further comprises visibility alarm relay means having visibility alarm relay contacts, a visibility alarm circuit connected to said visibility alarm relay contacts and adapted to generate said visibility alarm upon activation of said visibility alarm relay means; visibility alarm activating means for activating said visibility alarm relay in response to measuring signals indicating a visibility range less than a predetermined visibility range; wherein said automatic failure detection arrangement further comprises means for preventing the activation of the visibility alarm circuit during the operation of said automatic failure detection arrangement; means for adjusting said visibility alarm relay activating means so as to cause activation of said visibility alarm relay in response to said test measuring signal; and means for generating said failure signal upon failure of said visibility alarm relay contacts to operate.
Claim 8
Dependent Claim
39 words
An arrangement as set forth in claim 5, wherein said means for transmitting a test quantity of light directly from said transmitting means to said receiving means comprise a light guide interconnecting said transmitting means and said receiving means.
Claim 9
Dependent Claim
22 words
An arrangement as set forth in claim 7, further comprising means for operating said automatic failure detection apparatus automatically at predetermined intervals.
Claim 10
Dependent Claim
70 words
An arrangement as set forth in claim 8, wherein said means for operating said failure detection arrangement automatically at predetermined intervals comprise pulse generator means; and a plurality of counting stages having an input connected to said pulse generator means, and an output connected to said automatic failure detection arrangement in such a manner that said arrangement is activated after a predetermined number of pulses from said pulse generator means.
Claim 11
Dependent Claim
49 words
An arrangement as set forth in claim 5, wherein said failure signal generating means comprise a pair of normally closed failure alarm relay contacts of a failure alarm relay and wherein said activating means for activating said failure signal generating means comprise the coil of said failure alarm relay.
Claim 12
Dependent Claim
30 words
An arrangement as set forth in claim 10, wherein said activating means further comprise first bistable circuit means connected to said failure alarm relay coil for controlling the current therethrough.
Claim 13
Dependent Claim
34 words
An arrangement as set forth in claim 11, further comprising a first NAND having a first NAND gate output connected to said first bistable circuit means, and a plurality of first NAND gate inputs.
Claim 14
Dependent Claim
59 words
An arrangement as set forth in claim 12, wherein said means for blocking said scattered light from said receiving means comprise rotary magnet means, said rotary magnet means having a pair of contacts opened during failure detection; said automatic failure detection arrangement further comprising a pair of shunting contacts for shunting said rotary magnet contacts during automatic failure detection.
Claim 15
Dependent Claim
50 words
An arrangement as set forth in claim 13, further comprising detector means having a detector output connected to one of said NAND gate inputs, and adapted to furnish a signal to said one of said NAND gate inputs when said shunting contacts and said rotary relay contacts are opened simultaneously.
Claim 16
Dependent Claim
71 words
An arrangement as set forth in claim 14, further comprising a supply voltage source; voltage source discriminator means having a discriminator output connected to a further one of said NAND gate inputs, and a discriminator input connected to said supply voltage source, said voltage source discriminator means being adapted to furnish a signal to said further NAND gate input when the supply voltage is less than a predetermined minimum supply voltage.
Claim 17
Dependent Claim
23 words
An arrangement as set forth in claim 11, further comprising indicator means for indicating the state of activation of said failure alarm relay.
Claim 18
Dependent Claim
25 words
An arrangement as set forth in claim 12, wherein said timing circuit output is connected to a selected one of said first NAND gate inputs.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |