§
Luxuse
Patent Intelligence
Sign In
← Back to Patent Explorer
US3646352A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of measuring the concentration and/or size of suspended particles by forward scattering of light

Assignee: Bundesministerium fuer Wissenschaft
•
Filing: 1969-10-10
•
Granted: 1972-02-29
•
Expires: 1989-10-10
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A method for measuring the concentration and/or size of illuminated particles suspended in a gas by means of the scattered light process. The suspended particles are illuminated by passing them through a focused laser beam in the vicinity of its focal plane. The light that is scattered from the particles in the direction of propagation of the laser beam within an angle of + OR - 15* with respect to the focal line of the laser beam are then evaluated by a photodetector device to determine the desired parameter. The intensity of the laser beam is reduced if the anode current of the photodetector exceeds a preset limit. The output signal of the photodetector device is fed to a potentiometer which has a logarithmic resistance per unit of its length. The output of the potentiometer is fed to a fixed single channel pulse height analyzer, which records all the pulses above a predetermined threshold value and transmits them to a counter.

Inventors

  • 👤 Jan Bol
  • 👤 Werner Heinze
  • 👤 Josef Gebhardt
  • 👤 Werner Letschert

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 14:00
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/53

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 86 words
A method for measuring both separately and simultaneously the concentration and size of suspended particles, comprising the steps of: A. illuminating the particles by passing them through a focused laser beam at a point substantially in a focal plane defined by the laser beam; and b. detecting substantially all of the light scattered from the laser beam by the particles and substantially none of the unscattered light within an angle of + OR - 15* with respect to the direction of propagation of the laser beam.
Claim 2
Independent Claim 86 words
A method for measuring both separately and simultaneously the concentration and size of suspended particles, comprising the steps of: A. illuminating the particles by passing them through a focused laser beam at a point substantially in a focal plane defined by the laser beam; and b. detecting substantially all of the light scattered from the laser beam by the particles and substantially none of the unscattered light within an angle of + OR - 15* with respect to the direction of propagation of the laser beam.
Claim 3
Dependent Claim 39 words
The method of claim 1, wherein said detecting step includes the step of detecting the scattered light with a photodetector and reducing the intensity of the laser beam if the anode current of the photodetector exceeds a predetermined value.
Claim 4
Dependent Claim 22 words
The method of claim 2, further including the step of triggering a Kerr cell to reduce the intensity of the laser beam.
Claim 5
Dependent Claim 22 words
The method of claim 2, further including the step of triggering a Pockel cell to reduce the intensity of the laser beam.
Claim 6
Dependent Claim 31 words
The method of claim 2, wherein the detecting step further includes the step of feeding the output of the photodetector to a potentiometer having logarithmic resistance per unit of its length.
Claim 7
Dependent Claim 28 words
The method of claim 5, wherein the detecting step further includes the step of feeding the output of the potentiometer to a fixed single channel pulse height analyzer.
Claim 8
Dependent Claim 32 words
The method of claim 6, wherein the potentiometer has a tap, and is calibrated in particle sizes with a logarithmically subdivided scale, and the feeding from the potentiometer is at the tap.

References Cited (Backward Citations)

US3451755A Cited
US3418479A Cited
US3389259A Cited
US3515482A Cited
US3528742A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-02-28 1975-08-30 1976-02-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-02-28 1979-08-30 1980-02-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-02-28 1983-08-30 1984-02-29 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag