User Manual
3
DISPLAY PARAMETERS ON UEI COMBUSTION ANALYZERS
• TF = Flue Temperature: Calculate net temperature in °F or °C.
- Shows ambient temp after fresh air calibration and ‘-OC-’ when probe is disconnected.
• T = Net Temperature:
- Differential of flue temperature minus ambient (or inlet) temperature
- Differential of T1 - T2
• T∆ = Temperature Differential:
• O2 = Oxygen: O2 percentage displayed
• CO = Carbon Monoxide: CO ppm (parts per million) displayed.
-‘- - - -’ or ‘- OC -’ is displayed if there is a fault with the CO sensor or
the instrument has not been zeroed correctly, switch off instrument and try again.
• CO2 = Carbon Dioxide:
- EAGLE (C125 & C127) Calculated from the fuel selected and the measured O2 level
- EAGLE (C125 & C127) Will display ‘- - - -’ or ‘-O>-’ if the O2 level is too
high to calculate CO2 or in fresh air.
- Calculated value is only displayed during the combustion test.
- EAGLE X (C155 & C157) Direct measurement CO2 ppm (parts per million) displayed.
• X = Excess Air:
- Indicated as ‘XAIR %’ on the printout
- A calculated percentage of O2 above the theoretical level required for complete combustion.
- Is required to completely burn the fuel due to poor mixing and assisting in venting flue gases
- Only displays a reading during combustion test.
-‘- - - -’ or ‘-O>-’ is displayed in fresh air.
• EFF = Efficiency:
- Calculated based on gas readings, net temperature and fuel selected.
- Value is combustion efficiency, not appliance efficiency.
• ∆ = Loss:
- Total losses calculated from Combustion Theory. A summation of the next three parameters
• Dry %: Calculated heat lost turning the Carbon in the fuel to Carbon Dioxide (CO2)
• Wet %: Calculated heat lost turning the Hydrogen in the fuel into water (H2O)
• CO Loss %: Calculated loss due to partially burnt Carbon.
Any CO in the flue has the potential to be turned into CO2 releasing and losing more
heat up the flue.
• CO a = Carbon Monoxide Air-Free: Referenced to an oxygen level of 0%.
- Do not confuse this reading with the actual CO reading as detailed above.
- See the Combustion Efficiency Calculation sections for more details.
• AMB = Air Inlet:
- Temperature used to calculate the NET temperature.
• CO/CO2 = CO/CO2 Ratio: The ratio of measured CO divided by CO2.
- It gives an indication of:
• How good a gas sample the instrument is reading.
• How clean the boiler is running.
- 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 needing a major overhaul will show at least 0.008.
- Only displays a reading during combustion test. ‘- - - -’ is displayed while in fresh air.
• D = Draft Pressure
• P = Pressure
• NO = Nitric Oxide:
• -PO- = Pump Off:
- Measured gases will display this when pump is off.
• -O>- = High O2 level:
- Calculated values will display this when O2 levels are greater than 18%
- Values are calculated with fuel choice and the O2 readings
• -OC- = Probe Not Connected:
- Temperature values will display this when the probe is not connected or is open
- Press and hold the “PUMP” button to Zero the pressure sensor in selector positions that display
measured or calculated values “Aux” & “Flue Test”.
• N/F = Not Found:
- Displayed when not available or not installed ie: NO on a C155 or C125.
NOTE: See page 8 for complete auxiliary display listings.