Aethalometer
Model AE33
5.1 Basic calculations
The determination of the Black Carbon concentration is based on the measurement of light
absorption on a filter loaded with aerosols:
Light source
Optical attenuation:
Flow:
Attenuation coefficient:
Absorption coefficient:
Black carbon concentration:
Loading effect compensation:
Final equation:
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User's manual – Ver. 1.55
Optical detectors
Filter
= −100 ∗ ln (
*to get correct ATN, ATN0 must be subtracted from calculated ATN value
=
∗ ( 1 − )
∗ ( Δ 100
⁄
=
Δ
=
=
⁄
=
∗ ( Δ
=
( 1− ) ∗
∗∗ ( 1−∗
1
July 2017
Reference I
Sensing I
I
= reference signal;
(*)
⁄ )
0
0
I = spot signal
= measured flow
= leakage factor
)
S = spot area; t = time
C = multiple scattering parameter
(Weingartner et al. 2003)
= mass absorption cross-section
( 1 − ∗ )
k = compensation parameter
)
⁄
100
1
) ∗Δ
1
0
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