RKI Instruments GD-K77D - Manual (Page 38)

33 • Maintenance Model GD-K77D Operator’s Manual
7. Press the TEST/SET switch to put the unit in Zero Adjustment Mode.
8. Press the TEST/SET switch to zero the unit. The GD-K77D is finished adjusting the
zero after the display stops flashing.
9. Press the MODE switch to return to Maintenance Mode 2.
Setting the Span Adjustment: Part Two of Calibration
1. After setting the zero for the unit, use the FLOW ADJ switch to show 2-3 on the
display.
2. Press the TEST/SET switch to put the unit in Span Adjustment Mode.
3. Apply calibration gas for two minutes until the gas reading stabilizes.
4. After the reading has stabilized, use the FLOW ADJ switch to adjust the reading up or
down to match the concentration of the calibration gas.
5. Press the TEST/SET switch. The reading will flicker a few times and the unit will save
the span calibration and to return the unit to Maintenance Mode 2.
6. Disconnect the calibration gas.
7. Press and hold the MODE switch until the Skip lamp shuts off; this action will return
the unit to Detection Mode.
Other Adjustments
You can confirm the bias voltage of the unit, although the bias has been set at the factory.
You can also set the sensor’s start-up time using Maintenance Mode 2. Setting the start-
up time is done whenever the sensor is replaced in the GD-K77D.
Confirming Bias Voltage (Optional)
1. Turn on the power to the Model GD-K77D. See “Start Up” for more information.
2. Activate Maintenance Mode 1 by removing the Model GD-K77D’s cover, then pressing
and holding the Mode switch for three (3) seconds until 1-1 appears on the display
and the SKIP lamp flashes.
LED indication Display indication
PW/TR ALM1 ALM2 SKIP
2 3
LED indication Display indication
PW/TR ALM1 ALM2 SKIP
1 1