ABB AO2000-Fidas24 - Fidas24: Conversion of Concentration Data

AO2000 CONTINUOUS GAS ANALYZERS | OI/AO2000-EN REV. B 247
Fidas24: Conversion of concentration data
Various units for concentration data
When measuring organic carbon compounds (total C) the concentration is
indicated in various units. The most important units are:
• mg C/m
3
(e.g. for measurements in accordance with German 17. Federal
Regulation on Emissions)
• mg C
n
H
m
/m
3
• ppm C
n
H
m
(e.g. for measurements in accordance with German Federal
Regulations on Air Purity, details on test gas cylinders)
• ppm C1 (for TOC [total organic carbons] or methane CH
4
)
Examples for the conversion of units and concentration data
Conversion ppm to mg C
n
H
m
/m
3
m
3
mn
V
weightMolecular
ppm /mHC mg ×=
Conversion ppm to mg C/m
3
m
3
V
12.011 atoms C of Number
ppmm/C mg
×
×=
Conversion ppm to ppm C1
atoms C of Number ppm C1 ppm ×=
Example 1
The analyzer module has a measuring range of 0 to 50 mg C/m
3
. As a test
gas, propane (C
3
H
8
) in N
2
or in air is used.
What is the maximum test gas concentration in ppm or mg/m
3
for the
measuring range not to be exceeded?
83
C
m
HC
HCppm31.102
12.011 3
22.414 50
Matoms C of Number
VMR
[ppm]c
83
=
×
×
=
×
×
=
m
HCHC
3
HC
V
)Matoms H of Number Matoms C of (Number[ppm]c
][mg/mc
83
83
×+××
=
()
3
83
3
HC
/mHC mg 61.19
22.414
1.008 8 12.011 3 31.102
][mg/mc
83
=
×+××
=