•
Combustion Display 4
• Displays CO air free (-CF-)
CO air free takes into account excess air (make up air) and
factors this out of the displayed reading. Some systems
inject extra air to ensure complete combustion. This can
dilute the CO sample resulting in a low CO reading when the
standard CO display is being read.
This display should be used if the manufacturer specifications are stated
as CO air free. If it is used on a system that is not specified in CO air free
the displayed reading may appear abnormally high as compared to the
manufacturer specification.
The formula for CO air free is: COairfree = (20.9/20.9 - O2 meas.) x CO meas.
Pressing the Scroll Enter key changes the display:
•
Combustion Display 5
• Displays Temperature reading of Channel 1 (T1)
• Displays Temperature reading of Channel 2 (T2)
• Displays the Differential Temperature (Diff.) between ch1
and ch2
• 'oPEn' will be displayed if no 'K' type probe is connected to
the thermocouple socket
• Press the Up Arrow Key to switch between ºC and ºF
Pressing the Scroll Enter key again will make the display return to combus-
tion display 1 (Default display)
6. During a combustion test you can save, print, and send data to a comput-
er. See pages 25 through 31. Allow readings to stabilize before saving or
printing the data. Refer to page 19 for typical test results.
7. Pressure measurements can be made during a combustion test if required.
Refer to page21.
8. After the test is complete, remove the flue probe from the test location and
allow the analyzer to purge in a fresh air environment with the probe
attached. Make sure the analyzer purges to below 15ppm. Never remove the
battery to turn the analyzer off before the purge is complete. Refer to page 9
for complete instructions.
19
5. Allow the readings to stabilize. Multiple combustion analysis displays are
available to provide the various test results. Use the Scroll/Enter Key to move
through the various combustion displays.
•
Combustion Display 1 (Default Start Up Display)
• Displays Carbon Monoxide (CO) reading in parts per million
(ppm)
• Displays calculated Carbon Dioxide (CO2) figure in percentage
(%)
• Displays calculated CO/CO2 (Ratio) figure. The 712 calculates
this number by first converting the CO2 measurement from
percentage to ppm. The formula for this conversion is:
CO2ppm=(CO2%*10,000). This ratio is not used in any other
calculations. 10,000ppm = 1%
Pressing the Scroll Enter key changes the display:
•
Combustion Display 2
• Displays Oxygen (O2) reading in percentage (%)
• Displays calculated Excess Air (X Air) figure in percentage
• Displays calculated Efficiency (Eff.) figure in percentage
• Pressing the Up Arrow Key will toggle between Gross &
Net Efficiency
(Note: Gross Efficiency is used in the USA)
Pressing the Scroll Enter key changes the display:
•
Combustion Display 3
• Displays Carbon Monoxide (CO) reading in parts per million
(ppm)
• Displays Oxygen (O2) reading in percentage (%)
Pressing the Scroll Enter key changes the display: (Next Page)
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