User Manual

Model GD-K77D
Operator’s Manual Maintenance • 32
Calibration
Calibration requires you to perform both a zero adjustment and a span adjustment while in
Maintenance Mode 2. Calibration should be done on a periodic basis, or when you install
a new sensor or notice unusual gas readings. RKI Instruments Inc. recommends you
calibr ate the Model GD-K77D every si x mont hs .
NOTE: If the GD-K77D is installed in a clean room environment, the calibration frequency may be
extended to yearly.
Adjusting the Zero Setting
1. Turn on the power to the Model GD-K77D. See “Start Up” for more information.
2. Activate Maintenance Mode 1 by flipping up the control cover, then pressing and
holding the Mode switch for three (3) seconds until 1-1 appears on the display and the
SKIP lamp flashes.
3. Use the FLOW ADJ switch to indicate 1-3 on the display.
4. Press the TEST/SET switch. The disp lay will show “ADJ.”
5. Press and hold the TEST/SET switch until 2-1 appears on the display. The unit is now
in Maintenance Mode 2.
6. Use the FLOW ADJ switch to show 2-2 on the display.
LED indication
Display indication
PW/TR
ALM1
ALM2 SKIP
1
1
LED indication
Display indication
PW/TR
ALM1
ALM2 SKIP
1
3
LED indication
Display indication
PW/TR
ALM1
ALM2 SKIP
2
1
LED indication
Display indication
PW/TR
ALM1
ALM2 SKIP
2
2