Riken Keiki GX-2001 User manual

Model GX-2001
Operator’s Manual
Part Number: 71-0053RK
Revision: I
Released: 2/4/08
www.rkiinstruments.com

2 • Warranty Model GX-2001 Operator’s Manual
Warranty RKI Instruments, Inc., warrants the Model GX-2001 sold by us to be free
from defects in materials, workmanship, and performance for a period of
two years from the date of shipment from RKI Instruments, Inc. This
includes the instrument and the original sensors. Replacement parts are
warranted for 1 year from the date of their shipment from RKI Instruments,
Inc. Any parts found defective within their warranty period will be repaired
or replaced, at our option, free of charge. This warranty does not apply to
those items which by their nature are subject to deterioration or
consumption in normal service, and which must be cleaned, repaired, or
replaced on a routine basis. Examples of such items are:
Warranty is voided by abuse including mechanical damage, alteration,
rough handling, or repair procedures not in accordance with the instruction
manual. This warranty indicates the full extent of our liability, and we are
not responsible for removal or replacement costs, local repair costs,
transportation costs, or contingent expenses incurred without our prior
approval.
THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES
AND REPRESENTATIONS, EXPRESSED OR IMPLIED, AND ALL OTHER OBLIGATIONS
OR LIABILITIES ON THE PART OF RKI INSTRUMENTS, INC., INCLUDING BUT NOT
LIMITED TO THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. INNO EVENT SHALL RKI INSTRUMENTS, INC., BE LIABLE
FOR INDIRECT, INCIDENTAL, OR CONSEQUENTIAL LOSS OR DAMAGE OF ANY KIND
CONNECTED WITH THE USE OF ITS PRODUCTS OR FAILURE OF ITS PRODUCTS TO
FUNCTION OR OPERATE PROPERLY.
This warranty covers instruments and parts sold to users only by
authorized distributors, dealers, and representatives as appointed by RKI
Instruments, Inc.
We do not assume indemnification for any accident or damage caused by
the operation of this gas monitor and our warranty is limited to replacement
of parts or our complete goods.
Absorbent cartridges
Filter elements, disks, or sheets
Pump diaphragms and valves

Model GX-2001 Operator’s Manual Table of Contents • 3
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Sensor Retainer/Sensor Cover Retainer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Scrubber Filters/Sensor cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
LCD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Control Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Printed Circuit Boards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Alarm Lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Buzzer/Vibrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Battery Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Belt Clip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Battery Charger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Start Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Start-up Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Performing a Demand Zero. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Turning Off the Model GX-2001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Displaying Peak Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Displaying STEL and TWA Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Combustible Gas Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Aspirator Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Displaying and Setting the Alarm Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Setting the Time and Date. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4 • Table of Contents Model GX-2001 Operator’s Manual
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Setting the Zero Readings for All Target Gasses . . . . . . . . . . . . . . . . . . . . . . . . 28
Single Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Auto Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Recharging the Battery Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Replacing the Battery Pack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Replacing the Scrubber Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Replacing the Sensor Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Replacing a Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Rotating the Belt Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
WARNING: Understand manual before operating. Substitution of
components may impair intrinsic safety. To prevent
ignition of a hazardous atmosphere, batteries must only
be changed or charged in an area known to be
nonhazardous. Not tested in oxygen enriched
atmospheres (above 21%).

Model GX-2001 Operator’s Manual Introduction • 5
Introduction
Using an advanced detection system consisting of four gas sensors, the
Model GX-2001 Personal Four-Gas Monitor detects the presence of
combustible gas, oxygen (O2), carbon monoxide (CO), and hydrogen
sulfide (H2S) simultaneously. The Model GX-2001’s compact size and
easy-to-use design makes it ideally suited for a wide range of applications,
including sewage treatment plants, utility manholes, tunnels, hazardous
waste sites, power stations, petrochemical refineries, mines, paper mills,
drilling rigs, and fire fighting stations. The Model GX-2001 offers a full
range of features, including:
• Simultaneous four-gas monitoring of combustible gases, O2, CO, and
H2S
• Liquid crystal display (LCD) for complete and understandable
information at a glance
• Distinctive audible/vibrating alarms for dangerous gas conditions and
audible alarms for unit malfunction
• Glow in the dark control buttons.
• Microprocessor control for reliability, ease of use, and advanced
capabilities
• Alarm trend data
• Data logging functions
• STEL/TWA and over range alarm display
• Peak hold and average readouts
• Built-in time function
• RF shielded and high impact plastic case of very compact size and light
weight
• Belt clip for “hands-free” gas monitoring
• CSA classified for Class I, Division I, Groups A, B, C, and D hazardous
atmospheres
WARNING: The Model GX-2001 detects oxygen deficiency and
elevated levels of oxygen, combustible gases, carbon
monoxide, and hydrogen sulfide, all of which can be
dangerous or life threatening. When using the Model GX-
2001, you must follow the instructions and warnings in
this manual to assure proper and safe operation of the
unit and to minimize the risk of personal injury.

6 • Specifications Model GX-2001 Operator’s Manual
Specifications
Table 1: Model GX-2001 Specifications
Model Name Model GX-2001
Target Gas Combustibles
(Methane
calibration
standard)
Oxygen (O2) Hydrogen
Sulfide
(H2S)
Carbon
Monoxide
(CO)
Range
(Increment) 0-100% LEL (1% LEL) 0-40.0 vol% (0.1 vol%) 0-100 ppm (0.5 ppm) 0-500 ppm (1 ppm)
Detection
Method Diffusion
Response
Time T90 Within 30 Seconds
Display 7-Segment Digital LCD
Gas Alarms
(Factory
Settings)
Alarm 1: 10%
LEL
Alarm 2: 50%
LEL
Over: 100%
LEL
Alarm 1: 19.5
vol%
(Decreasing)
Alarm 2: 23.5
vol%
Over: 40.0
vol%
Alarm 1: 10
ppm
Alarm 2: 30
ppm
TWA: 10 ppm
STEL: 15 ppm
Alarm 1: 25
ppm
Alarm 2: 50
ppm
TWA: 25 ppm
STEL: 200
ppm
Operating
Temperature
and Humidity
-10 to 40oC/Below 85% RH (Without Condensation)
Safety/
Regulatory C US
186718
CSA classified, “C/US”, asIntrinsically Safe. Exia. Class I, Groups A,
B, C, &D. Class I, Zone 0, Group IIC. Temperature Code T3C.
Power Supply Ni-cad or Ni-MH Battery Pack (2.4 VDC Nominal), Direct Charging
Continuous
Operating
Hours
Up to 10 Hours (Non Alarm Operation After Full Charge), Ni-Cad
Up to 18 Hours (Non Alarm Operation After Full Charge), Ni-MH
Case High-impact Plastic, RF Shielded, Dust and Weather Proof
Required
Accessories Charger Station or Charger/Downloading Station w/Software & Cable

Model GX-2001 Operator’s Manual Specifications • 7
Other
Accessories • Charging Station with PC Communication Function for Datalog
Downloading
• Communication Computer Cable
• Communication Software (Windows®95, 98, NT)
• Automatic Calibration Station
• Hand Aspirated Sample Draw with Hose and Probe
• Wrist Strap (included with every unit)
• Neck Strap
Dimensions
and Weight Dimensions: 2.8 (H), 2.2 (W), 1.1 (D) inches Weight: Approximately 6 oz.
Table 1: Model GX-2001 Specifications
Model Name Model GX-2001

8 • Description Model GX-2001 Operator’s Manual
Description
This section describes the components of the Model GX-2001. These
components include the Model GX-2001’s case, sensors, LCD, control
buttons, printed circuit boards, alarm lights, buzzer/vibrator, battery pack,
belt clip, and battery charger.
Case
The Model GX-2001’s sturdy, high-impact plastic and metal case is radio
frequency (RF) resistant, and is suitable for use in many environmental
conditions, indoors and out. The unit is dust proof and weather resistant.
On the front of the case is a digital LCD, which shows gas concentrations,
battery level, time, and other readings including TWA, STEL, and peak gas
levels. Below the LCD are three glow in the dark control buttons. The first
button on the left is labeled MODE/POWER. The other buttons are labeled
DISP and AIR, respectively.
Sensor Cover Retainer
Sensor Retainer
MODE DISP AIR
HC
02
RKI
GX-2001
LCD
H2S
CO
Belt
Clip
Battery Charging
Contacts
IR Port
Control Buttons
POWER
Sensor Diffusion
Port, 4X
Alarm Lights
Figure 1: Components of the Model GX-2001

Model GX-2001 Operator’s Manual Description • 9
Beneath the control buttons is the buzzer/vibrator, which is located inside
the unit.
On the right side of the Model GX-2001 are the diffusion ports for the gas
sensors located inside the case. These sensors are, from top to bottom
(and are marked on the case), O2, HC (combustible gases), CO, and H2S.
On the left side of the case are two brass recharging contacts, which are
used when the unit is placed in the battery charger, and on top of the case
are two alarm lights. There is also an IR (infrared) communications port on
the left side which is used when downloading data to a computer using the
datalogging station. On the back of the unit is a rugged metal belt clip
enabling hands-free gas monitoring.The belt clip may be oriented as shown
in Figure 1 or rotated 180° depending on how the instrument is used.
Sensor Retainer/Sensor Cover Retainer
The sensorretainer holds the gas sensors in place and snaps onto the right
side of the case. It has 4 diffusion ports, one for each sensor, and has
recessed areas in it for the charcoal filter, the H2S removal filters, and the
sensor cover. The sensor cover retainer snaps onto the sensor retainer.
Two screws secure the sensor retainer and the sensor cover retainer to the
case.
Sensors
The Model GX-2001 uses four sensors to monitor HC (combustible gases),
O2, CO, and H2S simultaneously. The sensors are protected by filters that
allow atmosphere to diffuse inward. The sensors use different detection
principles, as described below.
Combustible Gas Sensor
The LEL sensor detects combustible gas and vapors in the atmosphere
with a catalytic element. 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 Model GX-2001’s
circuitry, converted to a measurement of combustible gas concentration,
and displayed on the LCD.
CAUTION: Do not expose the combustible sensor to high concentrations
of combustible gas such as that from a butane lighter.
Exposure to high concentrations of combustible gas may
adversely affect the performance of the sensor.

10 • Description Model GX-2001 Operator’s Manual
Oxygen Sensor
The O2sensor is a galvanic type of sensor. A membrane covers the cell
and allows gas to diffuse into the cell at a rate proportional to the partial
pressure of oxygen. The oxygen reacts in the cell and produces a voltage
proportional to the concentration of oxygen. The voltage is measured by
the Model GX-2001’s circuitry, converted to a measurement of gas
concentration, and displayed on the LCD.
CO and H2S Sensors
The CO and H2S sensors are electrochemical cells that consist of two
precious metal electrodes in an acid electrolyte. A gas permeable
membrane covers the sensor face and allows gas to diffuse into the
electrolyte. The gas reacts in the sensor and produces a current
proportional to the concentration of the target gas. The current is amplified
by the Model GX-2001’s circuitry, converted to a measurement of gas
concentration, and displayed on the LCD.
Scrubber Filters/Sensor Cover
Charcoal Filter Disk
The charcoal filter disk is located in the CO senor diffusion port of the
sensor retainer. It is black, has a woven texture, and is impregnated with an
H2S absorbing material. It fits into a recessed area of that port. The CO
sensor will respond if exposed to H2S and certain hydrocarbon gasses.
The charcoal filter scrubs these gasses out of the gas sampled to avoid
false CO readings. The H2S absorbing material added to the charcoal filter
extends it’s H2S absorbing life. If false or elevated CO readings are
noticed, especially in the presence of H2S, change the charcoal filter disk.
NOTE: Two H2S removal filter disks are used over the charcoal filter as
an additional guard against false CO readings as described below.
H2S Removal Filter Disks
The H2S removal filter disks are used in two locations. Two H2S removal
filter disks are located in a recessed area of the combustible gas sensor
diffusion port in the sensor retainer. Two are also used over the charcoal
filter disk in the CO diffusion port to extend the life of the charcoal filter. The
H2S removal filter disks are white when new. They scrub H2S out of thegas
sampled to increase the life of the combustible sensor and the charcoal
filter disk. They darken as they absorb H2S and must be changed when
they turn to a dark brown color. The recommended replacement frequency
will depend on how often the unit is exposed to H2S and the concentration.
Check the condition of the H2S removal filter disks quarterly.