RKI Instruments GX-2012 Manual - Manual (Page 176)

168 • Calibrating the GX-2012 GX-2012 Operator’s Manual
If any of the sensors cannot calibrate to the proper value, FAIL displays
along the bottom of the screen and the GX-2012 lists the sensor(s) that
failed to calibrate. In the example below, the OXY and H
2
S channels
failed calibration. The other sensors calibrated normally.
The buzzer and alarm lights activate. Press and release the RESET
SILENCE button after the buzzer and lights stop to reset the alarm and
return to the calibration menu. Attempt to calibrate again. If the failure
continues, investigate the cause. See “Troubleshooting” on page 143.
16. Disconnect the tubing from the probe.
17. If you have a 5 sensor unit and wish to calibration the %volume
combustible gas sensor, go back to step 1 and repeat the process,
selecting the %volume calibration gas value screen in step 12 and using a
%volume methane cylinder to fill your gas bag.
If you are finished calibrating, use the (SHIFT)T button to navigate to
the NORMAL menu item, then press and release the POWER ENTER
button to return to Measuring Mode.
Calibrating with the Single Calibration Method
This section describes calibration using the Single Calibration method.
To calibrate using the Auto Calibration method, see “Calibrating with the
Auto Calibration Method” on page 165.
The procedure below describes a span adjustment of one channel using a
calibration kit that includes a 4-gas calibration cylinder, a 0.5 LPM (liters per
minute) regulator, and non-absorbent sample tubing. The standard 4-gas
cylinder consists of 50% LEL methane, 12% oxygen, 50 ppm CO, 25 ppm
H
2
S, and a balance of nitrogen. In the example below, the CH
4
channel’s
span is adjusted. See “Parts List” on page 158 for available calibration kits
and calibration kit spare parts.
Calibration cylinders that contain only one target gas may also be used for
single calibration. For channels other than oxygen, RKI Instruments, Inc.
recommends that you use a cylinder that contains a concentration of 10-50%
of the full scale value of the target gas. For example, if you are calibrating the
%
ppm
MAINTENANCE
O
2
FAIL
H
2
S