Measuring Combustion Air Temperature; Flue Gas Measurement; Average Value Measurement - Dräger FG4500 Operating Instructions Manual

Operating Instructions Dräger FG4500

6.3 Measuring combustion air temperature

The FG4500 will now ask you to measure the combustion air tem-
perature. Place the flue gas probe in the inspection opening of the
combustion air intake or alternatively hold the flue gas probe in the
room air.
As soon as the combustion air values have stabilized, press Hold.
If an oxygen content of less than 21% is measured in the combus-
tion air supply, this implies under circumstances a leak in the ex-
haust pipe in the air-exhaust system.

6.4 Flue gas measurement

Within the exhaust stream, there are areas which only partially
mixed with exhaust. For this reason, it is necessary to take the
sample from the flow centre. The flow centre is characterized by
maximum flue gas temperature and minimum oxygen concentra-
tion.
Press the arrow button , once the combustion air meas-
urement is complete.
Now insert the flue gas probe into the exhaust pipe, move it in the
exhaust stream and position it so that the tip of the sensor is the
flow centre (maximum gas temperature, minimum oxygen concen-
tration). After you've found the flow centre and the measurement
values have stabilized, fix the flue gas probe in this optimal position with the sensor cone. A
summary of currently measured combustion values is then displayed. Then press the Hold
button and then the arrow button . By pressing the arrow button again,
you can display the other measurement results.

6.5 Average value measurement

The German regulation 1st BImSchV calls for simultaneous determination of oxygen content
and temperature of flue gas as an average over a time period of 30 seconds. If average
measurement is enabled in the settings, you can begin the 30-second averaging process by
pressing Start, no need to press Hold.
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Edition 01– May 2022
en