RKI Instruments GX-2003 Manual - Manual (Page 40)

33 • Calibration Mode GX-2003 Operator’s Manual
WARNING: 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-2003 with the regulator or
valve or damage to the pump will result. See “Appendix
A: Calibrating with a Sample Bag” on page 80 for
instructions to properly use a gas bag kit.
To calibrate 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 with a demand-flow
regulator and a 4-gas cylinder. This section also includes instructions
for calibrating one channel at a time using single calibration.
Preparing for Calibration
Whether you will calibrate the Model GX-2003 using auto calibration
or single calibration, you will need to set the fresh air readings first
before setting the span readings for each gas.
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-2003, Normal
Mode Only” on page 14 using the sample hose and probe.
3. With the unit on, perform a demand zero by pressing and holding
the ▲AIR button. The display prompts you to hold the ▲AIR
button.
4. Continue to hold the ▲AIR button until the display prompts you
to release the ▲AIR button. The GX-2003 will set the fresh air
reading for all channels.
5. Install the demand flow regulator onto the calibration cylinder.
6. Connect the sample tubing to the demand flow regulator.
Calibrating the GX-2003
From Measuring Mode, enter Calibration Mode by pressing and
holding the (SHIFT)▼ button, then pressing the DISPLAY(ADJ)
button and releasing both. If the unit prompts you for the password,
enter it by using the ▲AIR and (SHIFT)▼ buttons to select each
password number and then pressing and releasing POWER ENTER to
enter it and move on to the next one. The calibration menu displays
with the cursor next to AUTO CALIBRATION.