Aethalometer

Patent · Mon Jan 01 04:00:00 EST 1990

OSTI ID:867244

Hansen, Anthony D ^[1]

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1. Berkeley, CA

An improved aethalometer (10) having a single light source (18) and a single light detector (20) and two light paths (21, 22) from the light source (18) to the light detector (20). A quartz fiber filter (13) is inserted in the device, the filter (13) having a collection area (23) in one light path (21) and a reference area (24) in the other light path (22). A gas flow path (46) through the aethalometer housing (11) allows ambient air to flow through the collection area (23) of the filter (13) so that aerosol particles can be collected on the filter. A rotating disk (31) with an opening (33) therethrough allows light for the light source (18) to pass alternately through the two light paths (21, 22). The voltage output of the detector (20) is applied to a VCO (52) and the VCO pulses for light transmission separately through the two light paths (21, 22 ) are counted and compared to determine the absorption coefficient of the collected aerosol particles.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA
• DOE Contract Number: AC03-76SF00098
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4893934
• OSTI ID: 867244
• Country of Publication: United States
• Language: English

Related Subjects

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10
11
13
18
20
21
22
23
24
31
33
46
52
absorption
absorption coefficient
aerosol
aerosol particle
aerosol particles
aethalometer
air
allows
alternately
ambient
ambient air
applied
coefficient
collected
collection
compared
counted
detector
determine
device
disk
fiber
fiber filter
filter
flow
flow path
gas
gas flow
housing
improved
inserted
light
light detector
light path
light paths
light source
light transmission
output
particles
pass
path
paths
pulses
quartz
quartz fiber
reference
rotating
rotating disk
separately
single
single light
source
therethrough
transmission
vco
voltage
voltage output