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The menu » Calibration «
Zero-point calibration can be aborted at any time:
Use the » « key to move to » Back « and press the » « key.
Submenu » Span cal. «
The submenu » Span cal. « Contains all functions for calibrating the sensitiv-
ity of the installed sensor.
Sensitivity calibration
Calibration procedure (using an EC–H
2
S sensor as an example):
Select the menu items » Calibration «, » Span calibration « and » EC–
H
2
S « in this order, pressing the » « key after each selection.
— The maintenance signal is transmitted on the analogue interface.
— The alarm and fault relays are not triggered.
— The values for the calibration gas are displayed, for example:
— The calibration gas, concentration and unit can be changed:
Select » Cal. gas « and press the » « key. Select the desired calibration
gas from the list and press the » « key again.
Select » Concentr. « and press the » « key. Set the calibration gas con-
centration (same procedure as for input of a password).
Select » Unit « and press the » « key: Select the desired unit from the
list and press the » « key again.
If the settings agree with the available calibration gas:
Select » Next « and press the » « key.
— The message » Supply gas: H
2
S with flow rate 500 ml/min « is displayed.
— Connect calibration gas (see the information in the section "Maintenance"
on page 44) to the sensor.
Select » Next « and press the » « key.
— The current value and the expired time are now displayed.
When the displayed value has stabilised:
Select » Accept value « and press the » « key.
— In the display the maximum value and the current value as well as the re-
mainder of the sensor vitality are represented as a bar indication.
Cal. gas : H
2
S
Unit : ppm
Concentr. : 000025
OK
OK
OK
OK
OK
OK