GDS GasVac LG-1 Operating Handbook Download Page 31

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T E C H N O L O G I E S

Fig.1

Fig.2

Fig.3

Technical Sheet

ref C1698 Issue Bv.3

The Combi sensors which have an LCD display fitted also
incorporate 3 reed switches which can be activated using external
magnets through the glass window of the flameproof XDIwin
enclosure.

These magnets do not act instantly and have to

be in close proximity to L, M and R on the front display for

a few seconds to activate a software setup function.

The left magnet

enters the Auto zero ON or OFF menu.

This allows small drift changes in the sensor to be compensated
for but is not operational when the sensor readings are greater
than 5% of full scale. Therefore auto zero is inactive when a larger
gas reading is present. When the remove magnets message
appears, move the left magnet away and then the display shows
if auto zero is ON or OFF. The left magnet puts auto zero ON
and the right magnet turns it OFF. With no magnets present, the
display will return to normal after a few seconds timeout.

The right magnet

allows the CAN address of the sensor to be

changed. When the ADDRESS menu is displayed with a prompt
to remove the magnet, and then the display shows the address
and that the right magnet decreases it whilst the left magnet will
increase it. This is then stored in internal non volatile memory
and the display will automatically revert to normal operation.

The centre magnet

is used to inhibit the sensor. As with the left

and right magnet functions the display requests that you remove
the magnet and then the state of the inhibit appears on the LCD.
The left magnet then puts the sensor into inhibit whilst the right
magnet removes it. An amber LED on the front panel under the
LCD flashes when the sensor is inhibited. When all magnets are
removed, the display will revert to normal operation.

The left and right magnets together allow the calibration

menu to be used.

Removing both magnets as instructed on the LCD presents the
first part of this multi menu which is ZERO. With no gas present
use the left magnet to increase the reading and the right magnet
to decrease to achieve a zero reading on the display. A timer
is displayed on the LCD and when this reaches 0, the next
menu is displayed. This timer is 15 seconds approximately and
is reset back each time a magnet is near. Waiting till timeout
is acceptable but this timeout can be speeded up by placing a
magnet near to the centre position.

SPAN is the next part of the menu and gas should be applied to
the sensor at this time.

The left magnet increases the gain and the right magnet reduces
gain. The actual sensor value can be seen on the display to rise
or fall respectively.

LOW ALARM is the next menu and left and right magnets increase
and decrease this value.

HIGH ALARM is next followed by OVER RANGE alarm.

The direction of the alarms is displayed as ^ for rising and v for
falling but these can be changed using left and right magnets
together.

EOL

CAN

4-20

MPU

FAULT

TP1

TP11

TP9

TP5