Environnement AF22e, Техническое руководство, Страница: 31 / 118

Duplication prohibited
AF22e
Environnement
S.A
APRIL 2016
2–11
2.5 SIMPLIFIED CALCULATION DESCRIPTION
Calculations are performed following the steps below:
−
During a zero-ref cycle, the analyzer in zero air measurement mode acquires the following signals:
•
Dark PM sig.: PM signal is recorded when shutter is closed,
•
PM Ref. sig.: PM signal is recorded when shutter is open,
•
Dark UV sig.: photodiode UV signal is recorded when shutter is closed,
•
UV ref. sig.: photodiode UV signal is recorded when shutter is open.
−
Ratio calculation :
=
.
.
(Equation 1)
−
PM sig. (PM signal recorded on the ambient air) and UV sig. (UV photodiode signal recorded on
ambient air) acquisition.
−
Ratio calculation :
=
. .
. .
(Equation 2)
−
R
n
,…, R
n-3
are the R measurements at t
n
,…,t
n-3
times.
−
Rmoy
n
,…, Rmoy
n-3
are calculated for each t
n
,…,t
n-3
times by digital filtering of R
n
ratio with the
following equation :
=
1
× + × + × + ×
− × + × + ×
(Equation 3)
Where:
a
0
,…, a
3
and b
0
,…, b
3
are determined by calculation,
−
R
zero
ratio is Rmoy
n
saved after a zero-reference
−
Fluorescence calculation :
= −
(Equation 4)
−
Concentration calculation from linearization function :
Raw=F(Mean)
(Equation 5)
− Calibration, pressure and units correction application :
2 = × × ×
(Equation 6)