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Dräger Polytron 7000
Calibration
3. Select
Next
.
The current value and the gassing time are displayed.
In the case of EC-O
2
sensors, only checking of the zero-point value is
performed instead of zero adjustment. The zero-point value must be less than
0.6 volume percent. If this is not the case, an error is set in the sensor.
4. When the displayed measured value has stabilised (max. wait time = 3 minutes),
select
calibrate
.
5. End the zero gas supply.
6. Select
Back to menu
.
6.4 Span
calibration
Prerequisite:
– Zero adjustment has been performed (see section 6.3).
– Test gas supply is prepared (see section 6.2).
Span calibration can be aborted at any time. To abort during calibration, select
Previous
.
If no entries are made, the gas detector automatically switches over to measuring
mode after 15 minutes.
Procedure, using an EC-H
2
S sensor as an example
1. Select
Calibration
>
Span calibration
>
EC-H
2
S
.
The 4-20 mA interface issues the maintenance signal.
The values for the span calibration using the target are displayed.
Example:
"
Cal.gas : H
2
S
Cal.unit : ppm
Concentr.: 000025
"
If the displayed values do not match the target used, use the control keys to
adjust the values to the target gas.
2. Select
Next
3. Supply target gas:
Option
Description
Test gas cylinder
Set the pressure reducer to a flow rate of 500 mL/min.
Gas bag
Fill the gas bag using the test gas cylinder. Connect hose
leading to the pump module with gas bag.
Test gas cylinder
and flowmeter
Slowly open the pressure reducer of the test gas cylinder
until the flowmeter indicates a flow.
Option
Description
Test gas cylinder
Set the pressure reducer to a flow rate of 500 mL/min.
Test gas ampoule
Break the test-gas ampoule in the calibration flask.
Gas bag
Fill the gas bag using the test gas cylinder. Connect hose
leading to the pump module with gas bag.
Test gas cylinder
and flowmeter
Slowly open the pressure reducer of the test gas cylinder
until the flowmeter indicates a flow.
