KM9106 Operators Manual
58
CO/CO2 R :
The CO/CO2 ratio, is the ratio of measured CO divided by CO2.
It gives an indication of the following :-
•
How good a gas sample the instrument is reading.
•
How clean the boiler is running.
For example : A new or clean domestic boiler will display a ratio
of less than 0.004, a unit in need of cleaning 0.004-0.008 and a
unit in need of major overhaul will show greater than 0.008.
This only shows a reading when a combustion test is being
carried out. 0.0000 is displayed while in fresh air.
P INDEX :
The CO/CO2 ratio expressed as a percentage %, called the
‘Poison Index”
i.e. P INDEX % = 100 x CO/CO2. 0.00 is displayed while in
fresh air.
XAIR % :
Excess air calculated from the measured oxygen and type of fuel
used.
Displays reading during a combustion test. O2 > 20% is
displayed while in fresh air.
Prs :
Flue draught pressure reading. Displayed when pressure sensor
fitted. See section 4.5 for taking a reading and Section 6.4 for
changing for scale.
NO:
Nitric Oxide reading in ppm or mg/m3. Displayed when Nitric
Oxide sensor fitted. Reading can also be referenced to oxygen
ppmn or mg/m3n.
NO2:
Nitrogen Dioxide reading in ppm or mg/m3. Displayed when
Nitrogen Dioxide sensor fitted. Reading can also be referenced to
oxygen ppmn or mg/m3n.
NOx :
Calculated total Nitric oxides displayed in ppm or mg/m3.
For more details on NOx calculation see Section 6.4 Scales.
Reading can also be referenced to oxygen ppmn or mg/m3n.
SO2 :
Sulphur Dioxide reading in ppm or mg/m3. Displayed when
Sulphur Dioxide sensor fitted. Reading can also be referenced to
oxygen ppmn or mg/m3n.