Measuring; Preparing Measurements; Zeroing Phases; G.1 Preparing Measurements - TESTO 340 Instruction Manual

36 G. Measuring
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 flue 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 sufficient for systems dependent on ambient air.
However, the flue gas probe must be near the intake duct of the burner during the zero-
ing phase!
If an ambient air temperature sensor is connected, the ambient air temperature is
measured continuously via this sensor.
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.