Riken Keiki GX-2009 User Manual

GX-2009 Operator s Manual12
The charcoal filter scrubs these gasses out of the gas sampled to avoid
false CO readings. The H
2 S absorbing material added to the charcoal filter
extends it s H
2
S abs o rbing life . If fals e CO reading s are no tic e d, e s pe c ially
high readings in the presence of H
2
S, change the charcoal filter disk.
H
2 S Removal Filter Disks
Tw o H
2 S remo val filte r dis ks are lo c ate d in a rec es s e d area o f the
c o mbustible gas senso r diffusion po rt in the senso r retainer. The H
2 S
remo val filte r dis ks are white whe n ne w. They s c rub H
2
S o ut o f the g as
sampled to increase the life of the combustible sensor. They darken as
the y abs o rb H
2
S and must be changed when they turn to a dark brown
c o lo r. The re c o mme nde d re p lac e ment freq ue nc y will de pe nd o n ho w o fte n
the unit is exposed to H
2
S and the c o nc entratio n. Chec k the c o nditio n o f
the H
2
S remo val filte r dis ks q uarterly.
Sensor Cover
The sensor cover is white and protects the scrubber filters and sensors
from dust and water. It fits on the sensor retainer gasket over all the
sensor diffusion ports and is secured in place by the sensor cover retainer.
If the s enso r c o ve r be c o mes dirty, the respo nse time and ac c urac y o f the
GX-2009 will be affected. Replac e the sensor cover if it appears dirty.
Sensors
The GX-2009 uses four senso rs to monito r c o mbustible gases, O
2
, CO,
and H
2
S simultaneously. The sensors are protected from the environment
by the sensor c over which allows ambient air to diffuse to the sensors.
The sensors use different detection principles, as described below.
Combustible Gas (LEL) Sensor
The combustible gas sensor detects combustible gas and vapors in the
LEL (lower explosive limit) range with a catalytic element. A sintered metal
flame arrestor covers the element and allows ambient air to diffuse into
the sensor. The reaction of gas with oxygen on the catalyst causes a
change in the resistance of the element which affects the current flowing
thro ug h it. The c urrent is amplifie d by the GX-2009 s c irc uitry, c o nve rte d
to a measurement of combustible gas concentration, and displayed on
the LCD.
CAUTION : Do no t expo se the c o mbustible se nso r to high c o nc entratio ns
of combustible gas such as that from a butane lighter. Exposure
to high c o nc e ntratio ns o f c o mbustible g as may adverse ly affe c t
the performance of the sensor.
De s c riptio n
9

Riken Keiki GX-2009 Specifications

General

Brand	Riken Keiki
Model	GX-2009
Category	Monitor
Language	English