2.2.4.5
Measured conditions
Issue: A
Revision: 1
Date: 24/07/19
20.9% is taken as the level of free oxygen in dry air.
!
If the measured O
% is a wet measurement the measured O
2
concentration must be corrected to a dry measurement.
performed automatically by the software if the measured O
concentration is defined as a wet measurement; where :
(O
% measured) DRY = (O
% measured)WET x
2
2
If no correction is required for oxygen then standard O
If no correction is required for water vapour then H
After all these calculations have been performed the resulting measurement is
the effective mass concentration of the pollutant normalised to standard
3
conditions (in mg/Nm
).
Where measured values are required (e.g. to calculate rates of emissions) they
need to be recalculated for measured temperature and pressure as shown below
:
3
mg/m
=
substituting,
vpm
the measured mass concentration of the gas is;
3
mg/m
=
Ref: 100606
Section 2
General Description
100
100 - H
= O
measured.
2
2
O% = 0
2
N.vpm x 273 x measured pressure
T
standard pressure
=
ppm x standard pressure
measured pressure
N.ppm x 273
T
2
This is
2
O%
2
Page: 21
Need help?
Do you have a question about the Energy Tech 401 and is the answer not in the manual?