RKI Instruments GX-86A User Manual
Page 8

Model GX-86A Instruction Manual
RKI Instruments, Inc.
Page 7
atmosphere to diffuse inward. See Figure 3.
Combustible Gas Sensor
The LEL sensor detects combustible gas and vapors in the atmosphere
with a catalytic platinum element. The reaction of gas with oxygen on
the catalyst causes a change in the resistance of the element, which is
converted by the GX-86A into a reading of gas concentration.
The LEL sensor responds to a wide range of gases; see Appendix A
for the Relative Response Chart.
Oxygen Sensor
The O
2
sensor is an electrochemical cell, which reacts to the oxygen
in the atmosphere, producing a current proportional to the oxygen
concentration. This current is converted by the GX-86A into an
oxygen reading.
CO, and H
2
S (Toxics) Sensors
The toxics sensors are electrochemical cells, which react to gas in the
CO Sensor
O
2
Sensor
H
2
S Sensor
LEL Sensor
Sensor Cover
Spring Clips (2)
Figure 3. Sensors