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Dräger Polytron 7000
Calibration
2. Wait until the warm-up phase is completed.
Depending on the installed sensor, the warm-up phase can take between
5 minutes and 12 hours.
It is already possible to make settings in the menu:
3. Calibrate the sensor (see section 6).
4. Perform tests:
●
Check signal transmission to the control unit.
●
Test the alarm relay and the fault relay (only with relay mode, see
section 9.2.6).
5. If a pump module is used:
●
Check the aspiration path for tightness.
●
Compare the flow rate at the aspiration location and downstream of the gas
detector.
6 Calibration
Calibration involves adjusting the zero-point and the sensitivity of the sensor.
6.1 Test
gases
Depending on the type of calibration, different test gases are used.
Zero gas
Zero gas is a test gas used for zero-point adjustment. The zero gas used can be
fresh air from the ambient atmosphere. The fresh air must be free from the
measured gas or other substances that have cross-sensitivity. Nitrogen (N
2
) is used
in the case of O
2
sensors.
Target gas
Target gas is a test gas used for sensitivity adjustment. The target gas used can be
the measured gas or a surrogate gas. In the case of O
2
sensors, no target gas is
needed, and the oxygen from the ambient air (fresh air) is used.
6.2
Preparing the test gas supply
The mode of test gas supply depends on whether the gas detector is equipped with
a pump module or not.
Prerequisite:
– The warm-up phase of the sensor is completed (see section 5.5 Commissioning
