Schiltknecht Messtechnik ThermoAir6/64, Operating Instruction

Page: 25 / 51

ThermoAir6/64
24 Schiltknecht Messtechnik AG
Type of Operation
Thermoelectric probe
The probe has an NTC resistor which is maintained at a constant temperature
above the ambient temperature. The rate of flow is measured on the basis of
the heating power required for this. As this measurement is heavily dependent
on the ambient temperature, a second precision NTC resistor is used to
measure the ambient temperature, and compensation is made automatically.
Probe converter module
This unit contains the evaluation electronics for the probe. The measurement
converter module is calibrated together with the probe that will be used with
it. Therefore the converter card and the probe can not be replaced
individually! The instrument has the same serial number as its respective probe
(on rating plate).
Zero point adjustment:
-
Probe closed; wait for at least 3 minutes after closing.
-
At the LEMO socket (large) connect pin 1 to pin 5 for ca. 3 to 4 seconds;
then break the connection.
- After a waiting time of ca. 2 minutes, the probe is once more ready to
operate.
⇒
Do not leave pin 5 connected if no zero point adjustment is being
carried out!
⇒
Normally it will not be necessary to repeat the zero point adjustment.
However, after a long period of time or due to severe vibration during
transport, the setting can change (see also page 7).