Dräger PEX 3000

9023810 - 2nd edition - September 2005
Page 13 of 42
Calibration Menu
Calibration Menu
● To enter the calibration menu press the key l for more than one second but less
than 3 seconds. The display shows a flashing point on the right bottom indicating
the calibration mode.
ZE – Zero Adjustment
● Navigate by means of keys q or l until the display shows ZE (“ZEro“) and enter
the menu by pressing the keys (
q+l). The output signal switches to 3.4 mA.
— The display shows the currently measured gas concentration (negative values are
displayed as long as they are not lower than “–9“).
● Apply zero gas to the sensor and wait for signal stabilisation (max. 3 minutes.)
● Press keys (q+l) to save the displayed value as an up-dated zero point
● Press keys (q+l) again to terminate this function. The display shows ZE again.
● Press key l step into sensitivity adjustment
or
● Press key q to step back into measurement mode.
SP – Span Adjustment
● Navigate by means of keys q or l until the display shows SP (“SPan“) and enter
the menu by pressing the keys (
q+l).
— The display shows the span gas concentration used during the previous calibra-
tion procedure in % LEL.
— Adjust the concentration of the currently used span gas concentration by means
of key
q or l in steps of 1 % LEL between 20 and 99 % LEL (or in steps of
0.1 % LEL between 2.0 and 9.9 % LEL). Pressing the keys for longer activates a
repeat function.
● Press keys (q+l), apply span gas to the sensor and wait for signal stabilisation
(max. 3 minutes).
● Press keys (q+l) to calculate the necessary internal amplification and save it.
● Press keys (q+l) to display a reference value to characterise the sensitivity of the
sensor (constantly amplified bridge signal).
● Press keys (q+l) to terminate this function. The display shows SP again.
● Press key q twice to step back into measurement mode.
00723810_1.eps00823810_1.eps