Calibrating The Zero-Point - Dräger PEX 3000 Mode D'emploi

– Mentioning type XTR 0000 also includes type XTR 0001 as well as the
transmitters type XTR 0090 or XTR 0091 with remote sensing head SE Ex
PR ... DQ or HT M DQ (100 %LEL).
– Mentioning type XTR 0010 also includes type XTR 0011 as well as the
transmitters type XTR 0090 or XTR 0091 with remote sensing head SE Ex
LC ... DQ (10 %LEL).
4.4.2.1

Calibrating the zero-point

To enter the calibration menu, press the ▼ key for more than one second but
less than three seconds. The display shows ZE, and a flashing point on the
bottom right indicating the calibration mode.
– Confirm with keys (▲+▼). The measuring signal is set to 3.4 mA to indicate
the calibration mode to the controller.
– Apply gas to the sensor – either
– without a calibration adapter: Ensure that the transmitter is in clean
ambient air (no combustible gases or vapours present), or
– with a calibration adapter: Supply zero gas (clean air) at a flow rate of
approx. 0.5 L/min via the calibration adapter.
 The transmitter's display shows the current measured value for zero gas
and for clean ambient air, which generally differs slightly from zero.
Negative values down to "–9" %LEL or "–.9" %LEL (type XTR 0010) are
displayed.
– Wait until the reading has stabilised (max. 3 minutes) and press keys
(▲+▼). This converts the current sensor signal to the zero-point, and the
display shows the newly set zero-point (ideally "0").
– Press keys (▲+▼) to save the zero-point and exit the zero-point calibration.
WARNING
After a sensor replacement, the transmitter's zero-point may initially be
negatively misaligned so much that it cannot be displayed as a negative value.
The display then shows "--". In this case press keys (▲+▼) to save the new
zero-point and perform the zero-point calibration again, if necessary.
Dräger PEX 3000
– Press keys (▲+▼) to exit the zero-point calibration. The display shows ZE
once again.
– Press the ▲ key to return to the measuring mode or the ▼ key to calibrate
the span.
4.4.2.2 Calibrating the span
The zero-point must be calibrated before the span calibration!
– In the calibration menu, navigate using the ▲ or ▼ key until the display
shows SP ("SPan") and confirm by pressing the (▲+▼) keys. The
measuring signal is set to 3.4 mA to indicate the calibration mode to the
controller.
 The display shows the test gas concentration used during the previous
calibration in %LEL.
– Use the ▲ or ▼ key to set the concentration of the test gas currently in use
between 20 and 99 %LEL in 1 %LEL steps.
– For the type XTR 0010, a decimal point appears, i.e. the concentration of
the test gas can be adjusted between 2.0 and 9.9 %LEL in steps of
0.1 %LEL.
– Pressing the keys for a longer period activates the repeat function.
Recommended test gas concentration:
Transmitter Full-scale value
Type XTR 0000 100 %LEL
Type XTR 0010 10 %LEL
CAUTION
The test gas must consist of the gas component to be monitored and air.
Calibration gases filled in nitrogen are unsuitable for this task!
Operation
Test gas concentration
30 to 70 %LEL
3 to 7 %LEL