Method apparatus for aerosol particle absorption spectroscopy
1
New patents 857 4415265 ~~~0~ AND APPA~T~S FOR AEROSOL PARTICLE A3SOR~ION SPECTROSCOPY Anthony Campillo, Horn-Bond Lin assigned to The united States of America as represented by the United States department of Energy A method and apparatus for de~~i~ng the ab- sorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of elec~omagnetic energy which is scan- ned through the region of the s~~t~rn which is of interest. Particles exposed to the heating beam which have abso~tion bands within the band width of the heating beam absorb enerw from the beam. The particles are also illuminated by light of a wave length such that the light is scat- tered by the particles. The abso~tion spectra of the particles can thus be determined from an analysis of the scattered light since the absorp- tion of energy by the particles wili affect the way the light is scattered. Preferably the heating beam is modulate to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light wil1 also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an inter- ferometer and the scattered light reflects the Fourier Transform of the absorption spectra. SCANTING INTERFEROMETER CONTROL SYSTEMS David Abrams, Raul Curbelo, R Brough Turner assigned to Bio-Rad Laboratories Xnc A fanning interferometer is provided with a substantially monochromatic reference beam having a waveien~th outside the spectral region of principal interest. modulation of the reference beam provides a measure of the scan velocity that is compared with a stablized time reference to provide an error signai used to regulate the scan velocity. modulation of the reference beam also provides a fringe count. At a predestined count, the time reference is changed in a pre- arranged manner, providing a pre-establish~ sCan acc&ratiOn sequence at the end of each scan. The acceleration sequence is se&ted to in- sure the direction of the scan is reversed within a quarter wave interval of the fringe count, in- suring the fidelity of the fringe-count of the monochromatic reference source. 4412744 Jerald Lee, Charles D Reilly assigned to E I Du Pont de Nemours & Co An improved s~~ophotometer having a light source, a scanning type monochromator that provides light beams of different wavelengths over a light spectrum being scanned, and an ob- ject photometer for measuring the intensity of re- flected light from an object being tested and generating an electrica signal proportional t0 the intensity of the light measured and connected to means for recording the signal as a function of wavelength measured, the improvement used therewith comprising: {a) a beam spXitter that divides the beam exiting from the mono- chromator into first and second light beams, whereby the first beam is incident upon the ob- ject; (b) a reference photometer that measures the flux of the second light beam and generates an output electrical signal propo~ional to the in- tensity of the light measured; and (c) a light source control, connecting the reference photo- meter and the light source, which receives the electrical signal from the reference photometer and generates a feedback electrical signal to adjust the intensity of the light source to main- tain the reference photometer output electrical signal level constant across the light spectrum that is being scanned. The sp~trophotometer is useful for determining standard color values for coatings on substrates or for any colored surface. For ~~forrnati~~ about FATSEA~C~~ Pergamon Iaternati~naI lnformati~fl Corporation Pergamon lnfoLine Limited I340 Old Chain Bridge Road McLean, Virginia 22t01 12 Vandy Street London ECZA 2DE USA Telephone (703) 442-0900 England Telex: 90-181 I Telephone (01) 377-4650 Telex: 8814614 Pergamon Press Canada Ltd 150 Consumers Road, Suite 104 WjIl~wda~e, Ontario Canada M2J lP9 Telephone (416) 497-8337
Transcript of Method apparatus for aerosol particle absorption spectroscopy
New patents 857
4415265
~~~0~ AND APPA~T~S FOR AEROSOL PARTICLE
A3SOR~ION SPECTROSCOPY
Anthony Campillo, Horn-Bond Lin assigned to The united States of America as represented by the United States department of Energy
A method and apparatus for de~~i~ng the ab- sorption spectra, and other properties, of aerosol particles. A heating beam source provides a beam of elec~omagnetic energy which is scan- ned through the region of the s~~t~rn which is of interest. Particles exposed to the heating beam which have abso~tion bands within the band width of the heating beam absorb enerw from the beam. The particles are also illuminated by light of a wave length such that the light is scat- tered by the particles. The abso~tion spectra of the particles can thus be determined from an analysis of the scattered light since the absorp- tion of energy by the particles wili affect the way the light is scattered. Preferably the heating beam is modulate to simplify the analysis of the scattered light. In one embodiment the heating beam is intensity modulated so that the scattered light wil1 also be intensity modulated when the particles absorb energy. In another embodiment the heating beam passes through an inter- ferometer and the scattered light reflects the Fourier Transform of the absorption spectra.
SCANTING INTERFEROMETER CONTROL SYSTEMS
David Abrams, Raul Curbelo, R Brough Turner assigned to Bio-Rad Laboratories Xnc
A fanning interferometer is provided with a substantially monochromatic reference beam having a waveien~th outside the spectral region of principal interest. modulation of the reference beam provides a measure of the scan velocity that is compared with a stablized time reference
to provide an error signai used to regulate the scan velocity. modulation of the reference beam also provides a fringe count. At a predestined count, the time reference is changed in a pre- arranged manner, providing a pre-establish~ sCan acc&ratiOn sequence at the end of each scan. The acceleration sequence is se&ted to in- sure the direction of the scan is reversed within a quarter wave interval of the fringe count, in- suring the fidelity of the fringe-count of the monochromatic reference source.
4412744
Jerald Lee, Charles D Reilly assigned to E I Du Pont de Nemours & Co
An improved s~~ophotometer having a light source, a scanning type monochromator that provides light beams of different wavelengths over a light spectrum being scanned, and an ob- ject photometer for measuring the intensity of re- flected light from an object being tested and generating an electrica signal proportional t0 the intensity of the light measured and connected to means for recording the signal as a function of wavelength measured, the improvement used therewith comprising: {a) a beam spXitter that divides the beam exiting from the mono- chromator into first and second light beams, whereby the first beam is incident upon the ob- ject; (b) a reference photometer that measures the flux of the second light beam and generates an output electrical signal propo~ional to the in- tensity of the light measured; and (c) a light source control, connecting the reference photo- meter and the light source, which receives the electrical signal from the reference photometer and generates a feedback electrical signal to adjust the intensity of the light source to main- tain the reference photometer output electrical signal level constant across the light spectrum that is being scanned. The sp~trophotometer is useful for determining standard color values for coatings on substrates or for any colored surface.
For ~~forrnati~~ about FATSEA~C~~ Pergamon Iaternati~naI
lnformati~fl Corporation Pergamon lnfoLine
Limited I340 Old Chain Bridge Road
McLean, Virginia 22t01 12 Vandy Street
London ECZA 2DE USA
Telephone (703) 442-0900 England
Telex: 90-181 I Telephone (01) 377-4650
Telex: 8814614
Pergamon Press Canada Ltd
150 Consumers Road, Suite 104 WjIl~wda~e, Ontario
Canada M2J lP9 Telephone (416) 497-8337
