Method of optically measuring black carbon in the atmosphere and apparatus for carrying out the method
First Claim
1. A method of optically measuring black carbon in the atmosphere, comprising the steps of:
- depositing aerosols from a stream of air onto a filter tape,illuminating an aerosol particle collection area of said filter tape continually by an illumination source with light of one or more wavelengths,measuring simultaneously light fractions both transmitted through and reflected from said filter tape at several precisely defined angles/angle ranges by means of photodetectors arranged correspondingly relative to said illumination source in achieving maximum symmetry for the angles to be measured, anddetermining continually the loading of said filter tape collection area with light-absorbing aerosol material from the change in the optical properties of said collection area caused by said loading with the aid of known algorithms from transmissivities and reflectivities as detected.
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Accused Products
Abstract
For optically measuring black carbon in the atmosphere an aerosol particle collection area of a filter tape is continually illuminated by an illumination source with light of one or more wavelengths. Transmitted and reflected light fractions are measured at several precisely defined angles or angle ranges, such as of 0°, 120 to 140° and 165° to 180° by photodetectors arranged correspondingly relative to the illumination source, achieving maximum symmetry for the angles to be measured. The loading of the filter tape collection area with light absorbing aerosol material is continually determined from the change in the optical properties of the collection area with the aid of known algorithms from transmissivities and reflectivities as detected.
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Citations
9 Claims
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1. A method of optically measuring black carbon in the atmosphere, comprising the steps of:
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depositing aerosols from a stream of air onto a filter tape, illuminating an aerosol particle collection area of said filter tape continually by an illumination source with light of one or more wavelengths, measuring simultaneously light fractions both transmitted through and reflected from said filter tape at several precisely defined angles/angle ranges by means of photodetectors arranged correspondingly relative to said illumination source in achieving maximum symmetry for the angles to be measured, and determining continually the loading of said filter tape collection area with light-absorbing aerosol material from the change in the optical properties of said collection area caused by said loading with the aid of known algorithms from transmissivities and reflectivities as detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification