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

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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 ambient air temperature (AT)
If no ambient air temperature sensor is connected, the temperature measured by the
thermocouple of the fl ue gas probe during the zeroing phase is used as the ambient
air temperature. All dependent parameters are calculated by this value. This method
of measuring ambient air temperature is suffi cient for systems dependent on ambient
air. However, the fl ue gas probe must be near the intake duct of the burner during the
zeroing phase!
If an ambient air temperature sensor is connected, the ambient air temperature is
measured continuously via this sensor.
Gas zeroing
The fi rst time a gas measuring function is called up after the instrument has been swit-
ched on, the sensors are zeroed.
The fl ue gas probe may already be in the fl ue 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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