RKI Instruments GX-3R User manual

RKI Instruments, Inc.
www.rkiinstruments.com
GX-3R
Condensed Operator’s Manual
(go to www.rkiinstruments.com/product/gx-3r-gas-detector/ for full manual)
Part Number: 71-0523
Revision: A
Released: 1/17/23

2• GX-3R Condensed Operator’s Manual
WARNING
Read and understand this instruction manual before operating
instrument. Improper use of the gas monitor could result in bodily
harm or death.
Maintenance of the gas monitor is essential for proper operation and
correct readings.
Bump test the instrument before each day’s use with a known
concentration of each target gas. A bump test can be done in User
Mode’s BUMP item or by applying gas in Measuring Mode. The
instrument does not need to be calibrated unless it does not pass the
User Mode bump test or does not respond appropriately, as defined by
the user, in Measuring Mode. For more information about bump test
and calibration requirements, see IEC 60079-29-2.

GX-3R Condensed Operator’s Manual • 3
Table of Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
About the GX-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 2: Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Instrument Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Included Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Other Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Chapter 3: Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Turning On the GX-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Performing a Demand Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Turning Off the GX-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Measuring Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Monitoring an Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Combustible Gas Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Oxygen-Enriched Atmospheres. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
H2-Compensated CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Interference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Aspirator Adapter Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Alarm Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Responding to Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Chapter 4: Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Tips for Using Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4• GX-3R Condensed Operator’s Manual
Peak Screen (PEAK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
STEL Screen (STEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
TWA Screen (TWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Combustible Sensor Target Gas Conversion (LIST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Changing the User ID (USER ID) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Changing the Station ID (STN ID) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Last Successful Calibration Date (CAL DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Last Successful Bump Test Date (BUMP DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Date, Time, and Temperature Screen (TEMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Viewing Alarm Settings Screen (ALARM--PT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Chapter 5: User Mode and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Entering User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Tips for Using User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Performing a Bump Test (BUMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Chapter 6: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Instrument Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Recharging the Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Replacing the Buzzer Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Replacing the Sensor Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Replacing the Hydrophobic Dust Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Replacing a Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Replacing the Battery Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Chapter 7: Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Chapter 8: General Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Appendix A: Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

GX-3R Condensed Operator’s Manual • 5
Entering Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Tips for Using Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Appendix B: Gas Select Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Entering Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Tips for Using Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Appendix C: Interference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
ESR-A13i-H2S, H2S Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
ESR-A13P-CO, CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
ESR-A1CP-COH, H2-Compensated CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
ESR-A1DP-COHS, CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
ESR-A1DP-COHS, H2S Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
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.

6• Chapter 1: Introduction GX-3R Condensed Operator’s Manual
Chapter 1: Introduction
Overview
This chapter briefly describes the GX-3R gas monitor. This chapter also describes the
GX-3R Operator’s Manual (this document). Table 1 at the end of this chapter lists the specifications for the
GX-3R.
About the GX-3R
Using an advanced detection system consisting of up to three gas sensors, the GX-3R personal four-gas
monitor detects the presence of combustible gas, oxygen (O2), carbon monoxide (CO), and hydrogen
sulfide (H2S) simultaneously. The GX-3R’s compact size and easy-to-use design make 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 GX-3R offers a full range of features, including:
• Simultaneous monitoring of one to four gases
• Liquid crystal display (LCD) for complete and understandable information at a glance
• Ultrabright alarm LEDs
• Distinctive audible/vibrating alarms for dangerous gas conditions and audible alarms for unit
malfunction
• Microprocessor control for reliability, ease of use, and advanced capabilities
• Data logging functions
• Alarm trend data
• STEL, TWA, and over range alarms
• Peak readings
• Built-in time function
• Lunch break feature
• CSA “C/US” classified as intrinsically safe (see Table 2 on page 7)
WARNING: The Model GX-3R detects oxygen deficiency, elevated levels of oxygen, combustible
gases, carbon monoxide, and hydrogen sulfide, all of which can be dangerous or life
threatening. When using the GX-3R, 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. Be sure to maintain and periodically calibrate the GX-3R as described in
this manual.

GX-3R Condensed Operator’s Manual Chapter 1: Introduction • 7
Specifications
Table 1: Standard Sensor Specifications/Alarm Points
Combustible Gas,
Methane (CH4)
Calibration Standard*
Oxygen (O2)Hydrogen
Sulfide (H2S)
Carbon
Monoxide (CO)
Detection Range 0 - 100% LEL 0 - 40% volume 0 - 200.0 ppm 0 - 2000 ppm
Lower Detectable
Limit (LDL)
n/a n/a 0.5 ppm 2 ppm
Reading
Increment
1% LEL 0.1% volume 0.1 ppm 1 ppm
Warning
Setpoint
10% LEL 19.5% volume,
decreasing
5.0 ppm 25 ppm
Alarm
Setpoint
25% LEL 18.0% volume,
decreasing
30.0 ppm 50 ppm
Alarm H
Setpoint
50% LEL 23.5% volume,
increasing
100.0 ppm 1200 ppm
STEL Setpoint n/a n/a 5.0 ppm 200 ppm
TWA Setpoint n/a n/a 1.0 ppm 25 ppm
* The GX-3R is also available set up for general hydrocarbons and calibrated to a combustible gas other than methane,
such as isobutane. Consult RKI Instruments, Inc. for further information.
Table 2: GX-3R Specifications
Sampling Method Diffusion
Response Time T90 within 30 seconds
Display Graphics LCD Display
Environmental
Conditions
• 3000 meter maximum altitude
• Operating pressure: 70 - 120 kPa (70 - 110 kPa for explosion proof)
• Pollution degree 2
•IP66/68
Operating
Temperature &
Humidity
Continuous environment: -20°C to 50°C/Below 90% RH
Temporary environment (up to 15 minutes): -40°C to 60°C/Below 95% RH

8• Chapter 1: Introduction GX-3R Condensed Operator’s Manual
Safety/
Regulatory
• ATEX: Certificate Number: DEKRA 17ATEX0103 X
II1G Ex da ia IIC T4 Ga/IM1 Ex da ia I Ma (with NCR-6309)
II1G Ex ia IIC T4 Ga/IM1 Ex ia I Ma (without NCR-6309)
• IECEx: Certificate Number: IECEx DEK 17.0050X
Ex da ia IIC T4 Ga/Ex da ia I Ma (with NCR-6309)
Ex ia IIC T4 Ga/Ex ia I Ma (without NCR-6309)
• CSA classified, “C/US”, as Intrinsically Safe. Class I Division 1 Groups A, B, C, D T4.
Class I, Zones 0, A/Ex da ia IIC T4 Ga (with NCR-6309)
Class I, Zones 0, A/Ex ia IIC T4 Ga (without NCR-6309)
C US
186718
Power Supply Lithium ion battery pack (3.7 VDC, 200 mA)
Continuous
Operating Hours
@ 25 °C
With combustible gas sensor: 25 hours in Measuring Mode (non-alarm operation)
Without combustible gas sensor: 60 hours in Measuring Mode (non-alarm operation)
Battery
Charger Ratings
Input: 100 - 240 VAC, 47 - 63 Hz, 2.4 A
Output: 5.99 VDC, 2A max
Case High-impact Plastic, RF Shielded, Dust and Weather Proof (IP66/68)
Included
Accessories
• Alligator clip
• Rubber boot
• Wrist strap
• Calibration cup
• Single-unit charger
Other
Accessories
• 12 VDC adapter
• Multi-unit charger
• Belt clip
•SDM-3R
•RP-3R
• Aspirator adapter
• IrDA/USB Cable for connecting to a computer when using the Data Logger Management Program
(not needed if computer has an infrared port)
Dimensions and
Weight
Approximately 65(H) x 58(W) x 26(D) mm (2.6”H x 2.3”W x 1.0”D)
Approximately 100 g (3.5 oz.)
Table 2: GX-3R Specifications

GX-3R Condensed Operator’s Manual Chapter 1: Introduction • 9
About this Manual
The GX-3R Operator’s Manual uses the following conventions for notes, cautions, and warnings.
NOTE: Describes additional or critical information.
CAUTION: Describes potential damage to equipment.
WARNING: Describes potential danger that can result in injury or death.

10 • Chapter 2: Description GX-3R Condensed Operator’s Manual
Chapter 2: Description
Overview
This chapter describes the GX-3R instrument and its accessories.
Instrument Description
Case
The GX-3R’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 water resistant. A clear plastic
window on the front of the case allows for LCD viewing. The black bottom cover, located on the bottom of
the case, allows access to the filters and sensors. A sensor retainer and filter gasket help orient and retain
the sensor and filters.
Three threaded inserts on the back of the case allow for installation of an alligator clip or belt clip.
LCD
The digital LCD (liquid crystal display) simultaneously shows the gas reading for all installed sensors. The
LCD also shows information for each of the GX-3R’s operating modes.
WARNING: A thin protective film covers the display to prevent scratches during shipping. Remove
this film before use. Leaving the film installed voids the intrinsically safe certification.
GX-3R
POWER
MODE
CO/H2SLELO2
AIR
Bottom
Cover
Charging
Socket
Sensor
Retainer
Buzzer
Opening Front Back
LCDLEDs
Threaded
Inserts
Figure 1: Component Location