– 47 –
(1) NOx after O2 correction
CO after O2 correction
(a) Calculating equation
21 - On
C= • Cs
21 - OS
C: Concentration after O2 conversion
Cs: NOX or CO concentration measured
Os: O2 concentration measured
On: O2 concentration as conversion basic:
4% Oil combustion boiler
5% Gas combustion boiler
6% Solid object combustion boiler, petroleum heating furnace
12% Garbage incinerator
(b) Block diagram
Zurconia
type O
2
sensor O
2
converter O
2
signal
Infrared gas analyzer
Full scale is the same as
instantaneous value before
conversion.
O
2
/NO
x
conversion
or CO (ppm)
NO
x
or
CO signal
21 - On
21 - Os · Cs
(2) Moving average output
1 hr. moving average output (for NOx, SO2)
4 hr. moving average output (for CO)