User Manual

27 • Operation Model GD-K77D Operator’s Manu al

4. To return to Maintenance Mode item 1-1, press and release the Mode switch. To

return to Detection Mode, press and hold the Mode switch for three seconds.

CAUTION: The gas alarms will only work in Detec ti on Mod e. If the Model GD-K 77D is

left in Maintenance Mode for ten hours or more, it will switch to Detection

Mode automatically.

Maintenance Mode Summary

Mode No. Set Item Purp ose

1 - 1 Zero adjustment This zero adjustment is

done when unit calibration

is not required.

1 - 2 Alarm point check Used to confirm alarm

points of unit.

1 - 3 Maintenance check

mode

Used to put unit in Mainte-

nance Mode 2.

2 - 1 Check bias voltage This is an optional test.

The bias voltage is set at

the factory.

2 - 2 Zero adjustment Used when calibrating the

unit.

2 - 3 Span adjustment Used when calibrating the

unit.

2 - 4 Sen sor start-up

time

Used when new sensor is

installed.

LED indication

Display indication

PW/TR

ALM1

ALM2 SKIP