CODEL
OPS. 141
67
Issue : A
Revision : 1
Date : 14/06/18
Doc i/d :
0118/6
050028
Temperature Correction
Usually there is little change in temperature between the measured and exit
points, but where it is appreciable the stack exit opacity will be modified. This is
due to the gases reducing in volume while the particulate volume remains
relatively constant.
This correction is applied by expressing the effect in terms of measurement
path length as follows :
L
m
= L
mm
(273 + T
x
) / (273 + T
m
)
Where :
Lm
=
Temperature-corrected effective path length,
Lmm =
Actual measurement path length,
Tm
=
Temperature
o
C at measurement,
Tx
=
Temperature
o
C at stack exit.
