12 • Instrument Description
GX-2012 Operator’s Manual
Figure 2: Components of the GX-2012, Bottom
Case
The Model GX-2012’s sturdy, high-impact plastic case is radio frequency (RF) resistant
and is suitable for use in many environmental conditions, indoors and out. The case is dust
proof and weather resistant. A rubber layer on the outside of the case protects it from
scratches and impact damage.
A clear plastic window through which the LCD can be viewed is located on the front of
the case. Four brass charging contacts that are used when the GX-2012 is placed in the
charging station are on the back of the case. Both the rechargeable and alkaline versions
include a removable battery pack. The battery pack release latch is on the bottom. The
alkaline battery version also includes a battery cover release knob. The battery pack and
flow chamber are located on the back of the GX-2012. The inlet filter holder is located on
the top of the GX-2012 case.
Sensors
The GX-2012 uses up to five sensors to monitor combustible gas, oxygen (O
2
), carbon
monoxide (CO), and hydrogen sulfide (H
2
S) simultaneously. The sensors are located
inside the GX-2012 and are held in their sockets by the flow chamber. The sensors use
different detection principles, as described below.
Combustible Gas Sensors
% LEL/ppm Sensor (NC-6264A)
The % LEL/ppm sensor detects combustible gas in the % LEL and ppm range. It uses a
catalytic element for detection. The reaction of gas with oxygen on the catalyst causes a
change in the resistance of the element which affects the current flowing through it. The
current is amplified by the GX-2012’s circuitry, converted to a measurement of
combustible gas concentration, and displayed on the LCD.
Rechargeable Version
Battery Pack
Battery Pack
Release Latch
Battery Cover
Release Knob
Alkaline Version
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