ABB ACF5000 Manual page 75

ACF5000 FTIR ANALYZER SYSTEM
Example 2
If a test gas other than propane is used, its response factor must be taken
into consideration.
What is the maximum test gas concentration in ppm or mg/m
(CH ) is used?
4

MB

c [ppm]
CH
Number C atoms
4
c [ppm]
CH
3 
c [mg/m ]
4
CH
4

93.306

3
c [mg/m ]
CH
4
The response factor for methane is Rf
value is too great by this factor. In order to determine the maximum test gas
concentration to avoid exceeding the measuring range, the display of meas-
ured value must be divided by the response factor.
c [ppm]
CH

c [ppm]
4
maxCH
Rf
4
CH
4
c [mg/m
CH

3
c [mg/m ]
4
maxCH
Rf
4
CH
A test gas cylinder with approx. 80 ppm CH
centration in the test gas cylinder is 81.2 ppm CH
cate.
This is equivalent to a concentration of

c

3
c [mg C/m ] Bottle
CH
4

81.2 1
3 
c [mg C/m ]
CH
22.414
4
Considering the response factor, the indication should be adjusted to

c [mg C/m³] c
max CH CH
4 4
| OI/ACF5000-EN REV. A

V 50 22.414

m
 
M 1 12.011
C
 
(Number C atoms M
V
m
 
  
1 12.011 4 1.008

22.414
= 1.13; i.e. the display of measured
CH4
93.306
 
82.572 ppm
1.13
3
]
66.785
 
59.102
1.13
4
is ordered. The test gas con-
4

Number of C atoms M
C
V
m

12.011

43.513 mg C/m
  
Rf 43.513 1.13
CH
4
3 if methane

93.306 ppm CH
4
 
Number H atoms M
C H
3
66.785 mg CH /m
4
CH
4
3
mg CH /m
4
according to the certifi-
4
3

3
49.1697 mg C/m
75
)