4.3
Calibration menu
To enter the calibration menu press the ▼ key for more than one second but less than
3 seconds. The display shows a flashing point in the right bottom corner indicating the
calibration mode.
4.3.1
ZE – Zero point calibration
To calibrate the zero point, see Chapter 5.1.1 on Page 33.
4.3.2
SP – Sensitivity calibration
To calibrate the sensitivity,see Chapter 5.1.2 on Page 34.
4.4
Configuration menu
To enter the configuration menu press the ▼ key for more than 3 seconds until the display
shows "SL" and the point in the right bottom corner flashes to indicate the maintenance
mode.
NOTICE
i
i
This function can trigger alarms at the controller unit!
4.4.1
SL – Set power output to X mA
By means of this function the output signal of the PEX 1000 can be set to
certain constant values for test purposes.
1. Navigate by means of keys ▲ or ▼ until the display shows SL ("Set
Loop") and press keys (▲+▼) to confirm.
The power output is set to 4mA, the display shows "04".
2. By means of the keys ▲ or ▼ the power output can be adjusted to
values between 1 and 22 mA in steps of 1 mA. Pressing the keys for longer activates the
repeat function.
3. Press keys (▲+▼) to terminate this function. The display shows SL again.
4. Press key ▲ once to return to measuring mode.
4.4.2
CL – Calibrating the power signal
By means of this function the power output of the PEX 1000 can be
calibrated such that a current of 4 mA corresponds to 0 %LEL and a current
of 20 mA corresponds to 100 %LEL.
Generally the output signal can be measured at the controller side as voltage
drop across the input resistance; otherwise the 4 to 20 mA-loop has to be
interrupted to install an amp meter for this purpose.
1. Navigate by means of keys ▲ or ▼ until the display shows CL ("Calibrate Loop").
2. Press keys (▲+▼) to adjust the lower reference point, the display shows "04"
corresponding to 4 mA.
3. Measure the current by means of the amp meter or the controller unit.
4. Press the keys ▲ or ▼ to adjust the current output such that the amp meter reads a current
of 4 mA as accurately as possible (between 3.95 and 4.05 mA). Pressing the keys for
longer activates the repeat function.
5. Press keys (▲+▼). This saves the lower reference point, and the menu switches to the
upper reference point. The display shows "20" corresponding to 20 mA.
Dräger PEX 1000
Menu
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