Example Measurement; Correct Use Of The Flue Gas Probe - TESTO 300 XXL Instruction Manual

Example measurement

Correct use of the flue gas probe

20
The measurement of the flue gas temperature is made by
the thermocouple at the tip of the flue gas probe. The probe
tube protects the thermocouple, but has openings in to
allow the stream of flue gas to envelop the thermocouple.
The thermocouple must always be exposed to the stream
of flue gas to allow an exact measurement of the flue
gas temperature and thereby a precise determination of
the flue gas losses. It must not be screened by a web of
the probe pipe.
Flue gas
stream
The tip of the thermocouple must not touch the guard. If
necessary, bend the tip of the thermocouple accordingly.
The
measurement is made during the zeroing phase. The flue
gas probe can be adjusted in the flue at this time (Note: the
AT probe must be connected). This makes it possible to
conduct a core current search during the zeroing phase. The
temperature measured by the flue gas probe is interpreted
by the testo 300 XXL as the combustion air temperature
unless a AT probe is connected (Note: the probe must be
removed from the flue). When the zeroing phase has been
completed, this value is saved as the combustion air
temperature value.
All dependent parameters are calculated by this value.
incorrect
incorrect
Thermocouple
correct
correct
temperature