RKI Instruments GX-2012 Manual - Manual (Page 117)

GX-2012 Operator’s Manual Using Maintenance Mode • 109
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
combustible gas channel, your calibration cylinder should have a
combustible gas concentration between 10% LEL and 50% LEL. For the
oxygen channel, RKI Instruments, Inc. recommends using 100% nitrogen to
perform the adjustment but any concentration between 0% oxygen (100%
nitrogen) and 17% oxygen can be used to make the adjustment.
NOTE: If your combustible gas channel is calibrated to a gas other than
methane, use an appropriate gas cylinder to perform the calibration.
CAUTION: The single calibration method does not have a “FAIL”
notification. If a sensor cannot be set to agree with the
calibration source, see “Troubleshooting” on page 143.
1. Perform a fresh air adjust. See “Performing a Fresh Air Adjustment” on
page 103 for instructions.
2. Install the demand flow regulator onto the calibration cylinder.
3. Connect the sample tubing to the demand flow regulator.
4. Install the hose and probe to the GX-2012.
5. Use the AIRS or (SHIFT)T buttons to scroll to the ONE CAL menu
option.
MAINTENANCE
ONE CAL