TESTO 330 - Measuring

6 Using the product
55
6.2. Measuring
6.2.1. Preparing for measurement
It is assumed that the contents of the chapter First steps
(see First steps, page 33) are known.
6.2.1.1. Zeroing phases
Measuring the ambient air temperature (AT)
If no combustion air temperature probe is connected, the
temperature measured by the thermocouple of the flue gas probe
during the zeroing phase is used as the combustion air
temperature. All dependent measurement parameters are
calculated using this value. This method of measuring combustion
air temperature is sufficient for systems dependent on ambient air.
However, ensure that the flue gas probe is near the intake duct of
the burner during the zeroing phase.
If a combustion air temperature probe is connected, the combustion
air temperature is measured continuously via this probe.
Gas zeroing
When the instrument is switched on the measurement menu is
opened and the gas sensors are zeroed.
testo 330-1 LL: The flue gas probe must be in the open air
during the zeroing phase!
testo 330-2 LL: The flue gas probe can be in the flue gas
duct even during the zeroing phase, if a separate VT-
sensor is plugged in.
Draft / pressure zeroing
The pressure sensors are zeroed when a pressure measuring
function is called up.
testo 330-1 LL: The flue gas probe must be in the open air
during the zeroing phase / the instrument must not be
pressurized during zeroing!
testo 330-2 LL: The flue gas probe can be in the flue gas
duct even during the zeroing phase, if a separate VT-
sensor is plugged in. The pressure socket of the instrument
must be free (i.e. unpressurized, not closed).