Measuring; Preparing Measurements; Zeroing Phases - TESTO 340 Instruction Manual

G. Measuring
This chapter describes the measuring tasks that can be carried out with the product.
Familiarity with the contents of the chapter Operation (see p. 15) is assumed.
G.1 Preparing measurements
G.1.1 Zeroing phases
Measuring the combustion air temperature (AT)
If no combustion air temperature probe is connected, the temperature measured by
the thermocouple of the flue gas probe or the connected external thermocouple at the
probe socket during the zeroing phase is used as the combustion air temperature. All
dependent parameters are calculated using this value.
If an external thermocouple is connected at the probe socket, the flue gas probe
or the external thermocouple should not be in the flue gas duct during the zeroing
phase!
This method of measuring combustion air temperature is sufficient for systems depen-
dent on ambient air. However, ensure that the flue gas probe is near the intake duct of
the burner during the zeroing phase! Following the zeroing phase, the currently measu-
red temperature is displayed as the flue gas temperature (FT).
If a combustion air temperature probe is connected, the combustion air temperature is
measured continuously via this probe.
Gas zeroing
The first time a gas measuring function is called up after the instrument has been swit-
ched on, the sensors are zeroed.
The flue gas probe may already be in the flue gas duct during zeroing if a separate
AT sensor is connected.
Draught/pressure zeroing
The pressure sensors are zeroed when a pressure measuring function is called up.
The pressure sockets of the instrument must be free (i.e. unpressurized, not closed)
during zeroing.
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