Anapol EU-50, Operating Instructions And Equipment Description, Page: 39 / 41

11.1 Explanation of calculations
The following explanations are extracts from the BUWAL document:
"Recommendation for the measurement of exhaust gases from combustion systems for 'extra light'
heating oil or gas."
For the specification of the relative volume content, all gases are treated as "ideal gases" (volumetric
content = amount of substance)
1
.
In relation to standardised conditions: 1 mg / m 3 CO = 0.800 ppm mol
1 mg / m
3
= NO
2
= 0.487 ppm mol.
For conversion to NO
x
the measured value of NO in ppm is converted to NO
2
in mg / m
3 2
.
10 mg / m
3
are to be added to the converted NO measured value, as long as the NO measured value
exceeds 15 mg / m
3
.
11.1.1 Calculation NO
2
+ g
NO
x
= NO + NO
2
, specified as NO
2.
Example :
80 ppm NO / 0.487 = 164 mg / m3 NO2
NO2 + g = 164 + 10 = 174 mg / m3 NOx, specified on the measuring tape.
11.1.2 Calculation of exhaust gas losses qA
Calculation with A2 and B:
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
+
−
× − =
B
O
A
TA TG q
A
2
2
21
) (
A
q rend eta
− =
100 ) (
q
A
Exhaust gas losses as a %
TG Exhaust gas temperature in °C
TA Fresh air temperature in the immediate vicinity of burner air intake in °C
O
2
Oxygen content of dry exhaust gases as a % vol.
21 Oxygen content of air as a % vol.
A
2
, B Characteristics as per table:
Heating oil EL Natural gas Liquid gas and liquid gas/air mixture
A2 0.68 0.66 0.63
B 0.007 0.009 0.008
1 1 ppm mol = 10 -6 mol/mol = 10 -6 m 3 /m 3 = 1 ppm vol = 1 ppm, 1% vol = 1% mol = 1%
2 1 ppm NO is accepted as being equivalent to 1 ppm NO
2
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