US3711210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Smoke meter
Assignee: Individual
•
Filing: 1971-07-06
•
Granted: 1973-01-16
•
Expires: 1991-07-06
Abstract
Abstract A smoke meter where smoke flows between a light source and a photosensitive element which receives light from the light source, so that the extent to which light is received by the photosensitive element will be influenced by the opacity of the smoke. The light source is electrically connected to a meter which directly gives a reading of the opacity of the smoke. In order to compensate for any fluctuations in light other than the light travelling from the light source to the photosensitive element, a compensating lamp is provided to maintain at the photosensitive element a constant light level by compensating automatically for any fluctuations in light other than the light travelling from the light source to the photosensitive element, so that the latter will respond only to variations in light from the light source to provide an accurate indication of the opacity of the smoke.
Inventors
- 👤 R Krukowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:10
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/534
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
275 words
In a smoke meter, light source means for directing light along a predetermined path, photosensitive means situated along said path for receiving the light from said light source means, support means supporting said light source means and photosensitive means at a location where smoke to be tested will pass across said path between said light source means and photosensitive means, so that the extent to which light is received from said light source means by said photosensitive means will be determined by the degree of opacity of the smoke flowing across the path of light travelling from said light source means to said photosensitive means, meter means for providing an indication of the opacity of the smoke, electrical means operatively connected with said photosensitive means and meter means for operating the latter in accordance with light received by said photosensitive means from said light source means to indicate at said meter means the extent of opacity of the smoke flowing across the path of light travelling from said light source means to said photosensitive means, and compensating means electrically connected with said electrical means and carried by said support means for responding automatically to fluctuations in light received by said photosensitive means from any source other than said light source means and for providing an automatic compensation for said fluctuations in any light received by said photosensitive means other than the light travelling from said light source means to said photosensitive means, so thaT said photosensitive means will respond only to variations in the intensity of light from said light source means to prevent said meter means from being influenced by any other light variations.
Claim 2
Dependent Claim
275 words
In a smoke meter, light source means for directing light along a predetermined path, photosensitive means situated along said path for receiving the light from said light source means, support means supporting said light source means and photosensitive means at a location where smoke to be tested will pass across said path between said light source means and photosensitive means, so that the extent to which light is received from said light source means by said photosensitive means will be determined by the degree of opacity of the smoke flowing across the path of light travelling from said light source means to said photosensitive means, meter means for providing an indication of the opacity of the smoke, electrical means operatively connected with said photosensitive means and meter means for operating the latter in accordance with light received by said photosensitive means from said light source means to indicate at said meter means the extent of opacity of the smoke flowing across the path of light travelling from said light source means to said photosensitive means, and compensating means electrically connected with said electrical means and carried by said support means for responding automatically to fluctuations in light received by said photosensitive means from any source other than said light source means and for providing an automatic compensation for said fluctuations in any light received by said photosensitive means other than the light travelling from said light source means to said photosensitive means, so thaT said photosensitive means will respond only to variations in the intensity of light from said light source means to prevent said meter means from being influenced by any other light variations.
Claim 3
Dependent Claim
54 words
The combination of claim 1 and wherein said light source means provides light pulses of predetermined frequency and said photosensitive means responds to the amplitude of the light pulses for providing through said electrical means and meter means an indication of the opacity of smoke flowing between said light source means and photo-sensitive means.
Claim 4
Dependent Claim
106 words
The combination of claim 1 and wherein said compensating means includes a biasing lamp providing at least part of the light received by said photosensitive means from any source other than said light source means, said biasing lamp being connected by said electrical means to the output of said photosensitive means for maintaining a predetermined voltage offset at the output of said photosensitive means, said electrical means rebiasing said biasing lamp in response to fluctuations in light other than the light from said light source means to restore the predetermined voltage offset for maintaining constant any light other than the light from said light source means.
Claim 5
Dependent Claim
35 words
The combination of claim 3 and wherein said electrical means includes a direct-coupled amplifier and emitter-follower connected to said biasing lamp for maintaining automatically the predetermined voltage offset at the output of said photosensitive means.
Claim 6
Dependent Claim
19 words
The combination of claim 4 and wherein said photosensitive means is in the form of a silicon photo transistor.
Claim 7
Dependent Claim
40 words
The combination of claim 5 and wherein said light source means provides light pulses of predetermined frequency so that said photosensitive means responds to variations in the amplitude of the light pulses in accordance with the opacity of the smoke.
Claim 8
Dependent Claim
28 words
The combination of claim 6 and wherein said electrical means includes a band pass filter tuned to the frequency of the light pulses from said light source means.
Claim 9
Dependent Claim
21 words
The combination of claim 7 and wherein said electrical means also includes a holding circuit for storing a peak opacity reading.
Claim 10
Dependent Claim
90 words
The combination of claim 1 and wherein said support means is in the form of an open frame carrying said light source means and photosensitive means with the space therebetween open to the outer atmosphere for removably mounting said light source means and photosensitive means at the discharge end of an exhaust pipe of a motor vehicle on opposite sides of the path taken by the smoke issuing from the exhaust pipe, so that smoke issuing from the exhaust pipe will flow between the light source means and photosensitive means.
Claim 11
Dependent Claim
42 words
The combination of claim 9 and wherein said support means supports said light source means and photosensitive means for situating the path of travel of light from said light source means approximately six inches from the discharge end of the exhaust pipe.
Claim 12
Dependent Claim
19 words
The combination of claim 3 and wherein said biasing lamp of said compensating means is a tungsten biasing lamp.
Claim 13
Dependent Claim
42 words
The combination of claim 1 wherein said light source means includes a gallium phosphide lamp and a pulse generator operatively connected thereto for providing light pulses of predetermined frequency travelling along said path from said light source means to said photosensitive 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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |