RKI Instruments GD-K77D - Manual (Page 29)

Model GD-K77D Operator’s Manual Operation • 24
Maintenance Mode Operation Flow
CAUTION: When Maintenance Mode is entered during a gas alarm, the alarm condition will be cancelled.
The relay contact will be reset and the 4-20 mA output will lock on 2.5 mA.
Zero Adjustment
A zero adjustment resets the Model GD-K77D’s gas detecting system to zero so it can
accurately sample the target gas. This test should be done periodically, such as once a
month. This procedure illustrates how to use the zero function in Maintenance Mode 1. If a
full calibration is being done, use the zero function in Maintenance Mode 2 (see calibration
section).
PW/TR ALM1 ALM2 SKIP
PW/TR ALM1 ALM2 SKIP
LED indication Display indication
PW/TR ALM1 ALM2 SKIP
PW/TR ALM1 ALM2 SKIP
Press mode switch for
three seconds
Maintenance mode starts
1-1 Zero Adjustment
1-2 Alarm points
1-3 Maintenance mode 2
FLOW ADJ/select by ▲ ▼ SW
Maintenance Mode 1
FLOW ADJ/select by ▲ ▼ SW
1 1
1 2