MAGEE Scientific Aethalometer AE33 User Manual page 49

Aethalometer
Model AE33
Z
C
Kmax and Kmin The k value is the compensation parameter calculated for
Aff and Abb
Warmup
interval (min)
Tape adjust
(%)
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User's manual – Ver. 1.55
= 30. Choosing a lower limit on the attenuation range, ATNf 1
is needed to avoid filter matrix transients after the tape
advance. The upper limit ATNf 2 is set to be small enough not
to be influenced by the filter loading effect. For a more
detailed explanation see Drinovec et. al., 2015!
Zeta (Z) is the lateral airflow in the filter matrix under the
optical chamber, which has to be taken in to account because
the airflow is measured after the air passes the filter. This
value depends on filter tape material. Use the Z value
declared on the filter tape box! For filter tape type 8020 Z =
0.07, filter tape type 8050 Z = 0.025.
The enhancement of the optical absorption of aerosols by the
scattering of light in the filter is described by the factor C
(Weingartner et al., 2003). It depends on the filter material,
Cquartz = 2.14 for quartz filter and CTFE = 1.57 for TFE-
coated glass fiber filter (Drinovec et al., 2015). For filter tapes
part number 8020 and 8050, C equals 1.57.
each wavelength, they are reported in the data file. The limit
values should be set to 0.015 and -0.005 respectively. The
expected values for k are between 0 and 0.01.
The Angstrom exponent values for BC originating from fossil
fuel (Aff) and biomass burning (Abb). These are used for the
source apportionment algorithm which discriminates the
contribution of biomass burning and traffic to BC air pollution
(Sandradewi et al., 2008). Most frequently the values are set
to 1 for Aff and 2 for Abb.
The warm up interval occurs during each tape advance after
all calibrations are performed and is recommended to be kept
at 3 min.
Tape adjust can be used to adjust the spacing between two
consecutive measurements. I.e. if the spots between two tape
advances are overlapping the space between them can be
increased by increasing this number.
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