RKI Instruments GX-2012 Manual - Manual (Page 66)

58 • Calibration Mode GX-2012 Operator’s Manual
CAUTION: If you are using a calibration kit that includes a gas bag and a
fixed flow regulator or dispensing valve, do not apply gas
directly to the GX-2012 with the regulator or valve or damage to
the pump will result. See “Appendix A: Calibrating and Bump
Testing with a Sample Bag” on page 161 for instructions to
properly use a gas bag kit.
To calibrate or bump test the %LEL, Oxygen, CO, and H
2
S sensors at the
same time, automatically, with no need for a zero-oxygen source, you can use
the auto calibration feature with a 4-gas cylinder. If the H
2
S channel is not
active, then a 3-gas cylinder may be used for auto-calibration. This section
includes instructions for auto calibration and bump testing with a demand-
flow regulator, a 4-gas cylinder, and a %volume methane cylinder. This
section also includes instructions for calibrating one channel at a time using
single calibration.
NOTE: If the combustible gas channel(s) are calibrated to a gas other than
methane, use an appropriate multigas cylinder or use single
calibration to calibrate the combustible channel(s).
Preparing for Calibration or Bump Testing
Whether you will calibrate the GX-2012 using auto calibration, single
calibration, or perform a bump test, you will need to set the fresh air readings
first.
1. Find a fresh-air environment. This is an environment free of toxic or
combustible gases and of normal oxygen content (20.9%).
2. Turn on the unit as described in “Turning On the GX-2012, Normal Mode
Only” on page 19 or in “Turning On the GX-2012 in Normal Mode With
All Modes Active” on page 25. Use the sample hose and probe.
3. With the unit on, perform a fresh air adjustment by pressing and holding
the AIRS button. The display prompts you to hold the AIRS button.
4. Continue to hold the AIRS button until the display prompts you to
release it. The GX-2012 will set the fresh air reading for all channels as it
counts down from 8. If the combustible channel is set as %LEL only or
vol% only, there is no countdown period. The fresh air reading is set
immediately.
5. Install the demand flow regulator onto the calibration cylinder.
6. Connect the sample tubing to the demand flow regulator.