Patent US2034203A successfully refreshed from Google Patents.
Patent US3868186A successfully refreshed from Google Patents.
US3868186A
Expired / Lapsed
US
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Opacity meter
Assignee: Shell USA Inc
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Filing: 1974-03-04
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Granted: 1975-02-25
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Expires: 1994-03-04
Abstract
Abstract An opacity meter for measuring the light transmitted through a smoke plume using the sun as a light source and optics that limit the field of view to approximately 1* - 3* and produce a spectral response that approximates that of the human eye. The light transmitted is detected by a photodiode and the resulting electrical signal amplified and displayed on a meter that reads both the percentage of light transmitted and the corresponding Ringlemann number. The opacity meter also includes calibrating means using the sun as a reference to standardize the opacity meter prior to making measurements of a plume''s opacity.
Inventors
- 👤 Thomas T Paukert
- 👤 Eugene J Rosa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:57
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53; G01N21/534
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
241 words
A hand held opacity for measuring the light transmitted through a stack plume, said meter comprising: a housing having grip means disposed to permit an observer to simultaneously hold and operate said opacity meter; a lens system mounted in the housing to form a light transmission path having a first axis and disposed to limit the field of view of said opacity meter to less than 3*; a fixed filter means mounted in the housing and disposed in the light transmission path on said first axis, said fixed filter being disposed to produce a spectrum of light that approximates that observed by the human eye; a variable filter means mounted in the housing and disposed in the light transmission path on said first axis, said variable filter being manually adjustable to adjust the quantity of light transmitted along said transmission path to a predetermined value; a light sensitive detector mounted in the housing and disposed in the light transmission path on said first axis, said detector being sized and positioned in said light transmission path to supply an output signal proportional to the light transmitted through the plume; meter means coupled to said detector for displaying the magnitude of the detected signal; and optical means mounted in the housing and disposed to permit an observer to simultaneously observe along a second axis parallel to said first axis and spaced therefrom said meter means and the stack plume through said lens system.
Claim 2
Dependent Claim
241 words
A hand held opacity for measuring the light transmitted through a stack plume, said meter comprising: a housing having grip means disposed to permit an observer to simultaneously hold and operate said opacity meter; a lens system mounted in the housing to form a light transmission path having a first axis and disposed to limit the field of view of said opacity meter to less than 3*; a fixed filter means mounted in the housing and disposed in the light transmission path on said first axis, said fixed filter being disposed to produce a spectrum of light that approximates that observed by the human eye; a variable filter means mounted in the housing and disposed in the light transmission path on said first axis, said variable filter being manually adjustable to adjust the quantity of light transmitted along said transmission path to a predetermined value; a light sensitive detector mounted in the housing and disposed in the light transmission path on said first axis, said detector being sized and positioned in said light transmission path to supply an output signal proportional to the light transmitted through the plume; meter means coupled to said detector for displaying the magnitude of the detected signal; and optical means mounted in the housing and disposed to permit an observer to simultaneously observe along a second axis parallel to said first axis and spaced therefrom said meter means and the stack plume through said lens system.
Claim 3
Dependent Claim
17 words
The opacity meter of claim 1 wherein said detector is coupled to said meter through an amplifier.
Claim 4
Dependent Claim
37 words
The opacity meter of claim 1 wherein said optical means includes a half mirror disposed in the transmission path between said lens and said detector to direct a portion of the transmitted light on said optical means.
Claim 5
Dependent Claim
35 words
The opacity meter of claim 3 and in addition calibration means including means for setting said amplifier means at a reduced gain whereby said adjustable filter may be adjusted to provide a predetermined meter reading.
Claim 6
Dependent Claim
15 words
The opacity meter of claim 4 wherein said preset meter reading is approximately half scale.
Claim 7
Dependent Claim
46 words
The opacity meter of claim 1 wherein said variable filter comprises a first and second polarizing filter, said first filter being fixedly mounted and said second filter being movably mounted so that the alignment of the axes of said first and second filters may be varied.
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) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |