6
2.7 Operation via the Jack Plug
The LSG/LSK can be energised also via the jack plug. The allowed range is 6 to 14 Volt. For
switch on the LSG/LSK batteries must be inserted to the instrument. These batteries might
even be discharged.
3. Calibration
The calibration will be cleared via the 10Kohm jack plug. The red LED is blinking with 1 Hz.
To start the 1000 ppm calibration the sensor head has to be aerated. Starting with the “Hold”
button both buttons have to be pressed simultaneously until a signal can be heard and the red
LED is lightning permanently.
With the “Hold“ button the calibration value is taken.
In case the resistor value of the sensor is less than 50 % of the zero calibration the new
calibration is set and will be stored in the sensor head. Calibration is finished by this.
In case the resistor value is out of the foresaid range a permanent signal will sound. With the
“Hold” button a new calibration value can be taken or the calibration mode can be left via the
“I/O” button.
Together with the data for the 1000 ppm calibration the value of the zero point will be stored in
the sensor head. This zero point is relevant for the tolerance range for the future zero
calibration. Therefore its very important to ensure suitable conditions when making the factory
setting of the zero calibration! The detectable gas may not be in the ambient air!
The zero calibration will be done automatically after every warm-up phase. The resistance of the
sensor must be in the range of 0.333 to 3.0 of the value of the zero calibration stored in the
sensor head. Otherwise a failure message will be indicated.
Example : Stored value in the sensor head of the zero calibration: 15 KOhm
Min. resistance for the zero calibration: 5KOhm
Max. resistance for the zero calibration: 45KOhm
During calibration the function „automatic switch off“ is not active
The gas concentration will be indicated as bar graph.
During calibration a code will be stored in the EPROM of the sensor head for the sensor type
LSG respectively LSK. Afterwards the sensor head can just be operated with the same
instrument type.
Besides the calibration data the settings for the LCD lightning and the ppm beep will be stored
in the EPROM of the sensor head.
3.1 Change in the software for calibration V02
After clearance of the calibration via the „10KOhm lug jack“ the 10th bar will be displayed grey
blinking for the 1000 ppm concentration. Furthermore the red 3 mm LED is blinking with higher
frequency as soon as the concentration is between 800 ppm and 1200 ppm. When checking
the LSG/LSK with 1000 ppm span gas the bar indication must be between nine and eleven
bars. The function for zero setting via the mode button and the adjustment of different
sensitivities are blocked as soon as the calibration is cleared.
