RKI Instruments GX-2012 - Calibration Mode; Calibration;Bump Test Supplies and Equipment

GX-2012 Operator’s Manual Calibration Mode • 57
Calibration Mode
Calibration Mode allows you to calibrate the GX-2012’s sensor response and
to bump test the GX-2012.
The unit should be calibrated periodically. The optimum frequency of
calibration depends heavily on how the GX-2012 is used. For example,
instruments used daily may need to be calibrated weekly or monthly, while
instruments that are used only a few times a year may need to be calibrated
before each use. Typical calibration frequencies range from monthly to
quarterly.
You can program the GX-2012 to notify you when it is due for calibration.
See “Updating the Calibration Reminder Setting” on page 130.
Calibration/Bump Test Supplies and Equipment
To calibrate or bump test the GX-2012, you will need:
• Known calibrating samples of the gases being detected. The combustible
and toxic gas samples should have concentrations in approximately the
middle of the range of detection. An oxygen-free source, such as 100%
nitrogen is recommended for setting the oxygen zero when using single
calibration.
• A demand-flow regulator to provide adequate sample gas flow
• Non-absorbent tubing
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.