Operator`s manual

81 Preparing for Calibration GX-2003 Operator’s Manual
To calibrate the GX-2003, 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.
WARNING: When using auto calibration, the multi-gas cylinder
must have an oxygen concentration in the range of 10% -
18% oxygen.
A gas collection bag with hose clamp
A 0.5 LPM fixed-flow regulator or dispensing valve
Calibration tubing
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
document includes instructions for auto calibration with a fixed flow
regulator or dispensing valve and a 4-gas cylinder. This document
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” in the
GX-2003 Operator’s Manual 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.