Example Of Measurement; Measuring Flue Gas And Ambient Air Temperature - TESTO 325-3 Instruction Manual

Switch on
testo 325
Self-test
Battery capacity
USA V 13
6.0
Initialisation phase
43
The flue gas temperature is measured via the thermocouple at
the tip of the flue gas probe. The probe has openings in this area
in the probe stem so that the thermocouple is protected but at
the same time comes into contact with the flue gas.
In order to measure the exact flue gas temperature and therefore
be able to measure the exact flue gas loss, the thermocouple
should always be positioned in the flue gas flow. It should not
be covered by the probe stem frame. The flue gas probe
must be plugged into the FT connection socket.
Flue gas flow
The tip of the thermocouple should not touch the protection
casing. Bend back the tip of the thermocouple if necessary.
Wrong
There are two ways to measure the ambient air temperature with
testo 325:
1. Measuring the ambient air temperature using the flue gas
probe
The temperature is already measured during the initialisation
phase and is shown in the display.
The temperature measured by the flue gas probe is interpreted
by the testo 325 as the ambient air temperature and is saved
as the ambient air temperature value once the initialisation
phase is completed.
This type of ambient air temperature measurement is sufficient
for systems which are dependent on ambient air. During the
initialising phase, ensure that the tip of the flue gas probe is
held near the burner´s intake duct.
2. Measuring the ambient air temperature via a separate
ambient air probe
The probe is connected to the additional probe socket (AT) at
the bottom connection panel of testo 325. As soon as a
separate temperature probe is inserted, the temperature is
automatically recognised as the ambient air temperature and is
measured continually.
7

Example of measurement

Measuring flue gas and
ambient air temperature
Wrong
Thermocouple
Right
Right