Calibrating The Airflow Sensor; Air-Pressure-Independent Calibration - Bosch FAS-420-TT Series Operation Manual

Aspiration smoke detector LSN improved
Notice!
For a later evaluation of the airflow value, record the calibration type (see Calibrating the
airflow sensor, page 97 ), start-up temperature, air pressure and height above sea level in the
test log.
Once the airflow sensor has been calibrated, no further changes may be made to the pipe
system.
If changes are necessary at a later time, the airflow sensor must be re-calibrated (see
Calibrating the airflow sensor, page 97 ).
7.2

Calibrating the airflow sensor

Notice!
The Aspiration smoke detector must be operated for at least 30 min prior to the airflow being
initialized to bring it up to operating temperature.
Described below is the procedure for calibrating the airflow sensor, both irrespective of air
pressure, i.e. in simplified form, and depending on air pressure..
For an air-pressure-dependent calibration, use the air pressure correction tables in the
appendix.
To be able to judge the airflow sensor value correctly during start-up work, always adhere to
the type of calibration in the test log.
7.2.1

Air-Pressure-Independent Calibration

Air-pressure-independent calibration of the airflow sensor
1.
2.
3.
No further modifications may be made to the pipe system during or after initialization. The fan
voltage must also remain unchanged following initialization. Otherwise, the initialization
procedure must be repeated.
Bosch Sicherheitssysteme GmbH
1
2
Make sure that the aspirating smoke detector has been operating for at least 30 minutes.
To initialize the connected pipe system, press the S2 flow-init button on the detector
module concerned, until the green operating LED on the unit starts to flash. Initialization
is complete after approx. 5 s. Following successful initialization, the operating LED lights
up permanently.
Connect the housing to the FAS‑420 and check that it is correctly positioned.
Operation guide
Commissioning | en
1 Detector module
2 S2 flow-init button
2020.04 | 6.1 | F.01U.029.275
97