RKI Instruments GX-3R Pro User manual

RKI Instruments, Inc.
www.rkiinstruments.com
GX-3R Pro
Operator’s Manual
Part Number: 71-0478
Revision: 0
Released: 5/17/22

GX-3R Pro Operator’s Manual • 2
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 TEST 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.

3• GX-3R Pro Operator’s Manual
Table of Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
About the GX-3R Pro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Chapter 2: Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Instrument Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
LCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Control Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Alarm LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Buzzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Vibrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Infrared Communications Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Battery Pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Included Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Alligator Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Rubber Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Wrist Strap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Single-Unit AC Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Calibration Cup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Other Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
12 VDC Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Multi-Unit AC Charger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Belt Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
SDM-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
RP-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Aspirator Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
IrDA Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Chapter 3: Measuring Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

GX-3R Pro Operator’s Manual • 4
Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Turning On the GX-3R Pro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Performing a Demand Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Turning Off the GX-3R Pro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Measuring Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Monitoring an Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Combustible Gas Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Oxygen-Enriched Atmospheres. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
H2-Compensated CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Interference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
CO2 Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Aspirator Adapter Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Alarm Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Responding to Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Chapter 4: Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Tips for Using Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Peak Screen (PEAK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
STEL Screen (STEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
TWA Screen (TWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Combustible Sensor Target Gas Conversion (HC GAS LIST). . . . . . . . . . . . . . . . . . . . . 48
User ID Screen (USER ID). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Station ID Screen (STATION ID). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Last Successful Calibration Date (CAL DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Last Successful Bump Test Date (BUMP DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Date, Time, and Temperature Screen (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Alarm Points Screen (ALARM POINTS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Screen Inversion On/Off (INVERT SELECT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
LCD Color Scheme (LCD BACKGROUND) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Turning Bluetooth On/Off (BLUETOOTH). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Adjusting the Buzzer Volume (BUZZER VOLUME) . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Changing Instrument Language Back to English (LANGUAGE) . . . . . . . . . . . . . . . . . . 58
Chapter 5: User Mode and Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Entering User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Tips for Using User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Performing a Bump Test (BUMP TEST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

5• GX-3R Pro Operator’s Manual
Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Setting Calibration Parameters (CAL SETTING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Setting Bump Test Parameters (BUMP SETTING) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Adjusting Man Down and Panic Settings (MAN DOWN). . . . . . . . . . . . . . . . . . . . . . . . 98
Alarm Settings (ALARM SETTING). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Updating the Lunch Break Setting (LUNCH BREAK) . . . . . . . . . . . . . . . . . . . . . . . . . 105
Setting the Confirmation Beep and Non-Compliance Indicator (CONFIRMATION). . 105
Auto Backlight in Low Light (AUTO BACKLIGHT) . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Updating the Backlight Time (BACKLIGHT TIME). . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Turning the Key Tone On/Off (KEY TONE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Display Mode Items (D MODE SETTING). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Reading Units for IR Sensor (IR UNIT SELECT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
CO2 Fresh Air Adjustment On/Off (CO2 AIR SETTING) . . . . . . . . . . . . . . . . . . . . . . 111
Setting the Date/Time (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Setting the Date Format (DATE FORMAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Changing the Instrument Language (LANGUAGE) . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Turning the Password On/Off (USER PASSWORD). . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Viewing the ROM/SUM (ROM/SUM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Viewing the Radio Standards (RADIO STANDARD). . . . . . . . . . . . . . . . . . . . . . . . . . 115
Returning to Measuring Mode (START MEASURE) . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Chapter 6: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Instrument Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Replacing the Batteries (Alkaline Version). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Recharging the Batteries (Li-ion Version) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Replacing the Buzzer Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Replacing the Sensor Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Replacing the Hydrophobic Dust Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Replacing a Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Replacing the Battery Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
Chapter 7: Storage and Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133
Chapter 8: General Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134
Appendix A: RK Link Phone App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
Installing the App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Important Setup Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Pairing a GX-3R Pro. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

GX-3R Pro Operator’s Manual • 6
Searching for a Paired GX-3R Pro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Disconnecting a Paired GX-3R Pro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Adjusting App Notification Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Defining Owner Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Setting Up Email/Text Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Changing GX-3R Pro Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Alarm Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Calibration and Bump Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Backlight Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Logger Data Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Viewing Serial Number, IDs, and Bump/Cal Information . . . . . . . . . . . . . . . . . . . . . . . 165
Viewing App Version Info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Appendix B: Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .170
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Entering Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Tips for Using Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Performing a Gas Test (GAS TEST). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Sensor/Battery Replacement Date (SENSOR DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Performing a Bump Test (BUMP TEST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Setting Alarms to Latching or Self-Resetting (LATCHING) . . . . . . . . . . . . . . . . . . . . . 178
Turning Demand Zero On/Off (DEMAND ZERO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Turning Auto Zero On/Off (AUTO ZERO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Turning ID Display Function On/Off (ID DISPLAY) . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Turning Zero Suppression On/Off (ZERO SUPPRESS) . . . . . . . . . . . . . . . . . . . . . . . . 180
Turning Zero Follower On/Off (ZERO FOLLOWER) . . . . . . . . . . . . . . . . . . . . . . . . . 180
User Mode Zero Suppression (DISP ZERO SUP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
User Mode Zero Follower (DISP ZERO FLWR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Setting the Date/Time (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Setting the Date Format (DATE FORMAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Setting the Instrument Language (LANGUAGE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Turning the Password On/Off (MAINT PASSWORD) . . . . . . . . . . . . . . . . . . . . . . . . . 183
Viewing the ROM/SUM (ROM/SUM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Adjusting the LCD’s Contrast (LCD CONTRAST). . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Performing a Default (M.DEFAULT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Exiting Maintenance Mode (START MEASURE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Appendix C: Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

7• GX-3R Pro Operator’s Manual
Entering Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Tips for Using Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Changing the Gas Combination (GAS COMBO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Saving the Alarm Points (SAVE ALARM-P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Turning the Calibration Max Span On/Off (DISP MAX SPAN) . . . . . . . . . . . . . . . . . . 193
Stealth and Vibrator Settings (STEALTH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
LEL Definition (CHANGE LEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Exiting Gas Select Mode (START MEASURE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Appendix D: Interference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197
ESR-A13D-HCN, HCN Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
ESR-A13D-NO2, NO2Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
ESR-A13D-PH3, PH3Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
ESR-A13D-SO2, SO2Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
ESR-A13i-H2S, H2S Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
ESR-A13P-CO, CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
ESR-A1CP-COH, H2-Compensated CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
ESR-A1DP-COHS, CO Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
ESR-A1DP-COHS, H2S Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
ESR-B134-NH3, NH3Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
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.
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214

GX-3R Pro Operator’s Manual Chapter 1: Introduction • 8
Chapter 1: Introduction
Overview
This chapter briefly describes the GX-3R Pro gas monitor. This chapter also describes the
GX-3R Pro Operator’s Manual (this document). Table 1 at the end of this chapter lists the
specifications for the GX-3R Pro.
About the GX-3R Pro
Using an advanced detection system consisting of up to four gas sensors, the GX-3R Pro personal
five-gas monitor detects the presence of combustible gas, oxygen (O2), carbon monoxide (CO),
hydrogen sulfide (H2S), and CO2or a super toxic gas simultaneously. The GX-3R Pro’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
Pro offers a full range of features, including:
• Simultaneous monitoring of one to five 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 on page 9)
WARNING: The Model GX-3R Pro 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 Pro, 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 Pro as described in this manual.

9• Chapter 1: Introduction GX-3R Pro Operator’s Manual
Specifications
Table 1: Standard Sensor Specifications
Combustible Gas, Methane
(CH4) Calibration Standard* Oxygen (O2)Hydrogen Sulfide (H2S)
Carbon
Monoxide (CO)
Detection Range 0 - 100% LEL 0 - 40.0% volume 0 - 200.0 ppm 0 - 2000 ppm
Lower
Detectable
Limit (LDL)
n/a n/a 0.5 ppm 3 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
Indication
Accuracy
• Continuous environment (-20°C
to 50°C): ± 5% of reading or ±
2% LEL (whichever is greater)
• Temporary environment (-40°C
to
-21°C and 51°C to 60°C): ± 10%
LEL
• 0 - 25.0%:
± 0.5% O2
• 25.1 - 40.0%:
± 3.0% O2
• 0 - 100 ppm:
± 5% of
reading or ± 2
ppm H2S
(whichever is
greater)
• 101 - 200 ppm:
± 20% of
reading
• 0 - 500 ppm: ±
5% of reading or
± 5 ppm CO
(whichever is
greater)
• 501 - 2000 ppm:
± 20% of reading
* The GX-3R Pro 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: IR Sensor Specifications
Carbon Dioxide (CO2)
Detection Range 0 - 10.00% volume 0 - 10,000 ppm
Lower Detectable
Limit (LDL)
0.05% volume 300 ppm

GX-3R Pro Operator’s Manual Chapter 1: Introduction • 10
Reading
Increment
0.01% volume 20 ppm
Warning
Setpoint
0.50% volume 5,000 ppm
Alarm
Setpoint
3.00% volume 5,000 ppm
Alarm H
Setpoint
3.00% volume 5,000 ppm
STEL Setpoint 3.00% volume n/a
TWA Setpoint 0.50% volume 5,000 ppm
Indication
Accuracy
• 0 - 5.00%: ± 5% of
reading or ± 2% of full
scale (whichever is
greater)
• 5.01 - 10.00%: ± 20% of
reading
• ± 5% of reading or
± 2% of full scale
(whichever is
greater)
Table 3: EC Sensor Specifications
Ammonia
(NH3)
Hydrogen
Cyanide
(HCN)
Nitrogen
Dioxide
(NO2)
Phosphine
(PH3)
Sulfur
Dioxide (SO2)
Detection Range
and Service Range
0 - 400.0 ppm
(parts per mil-
lion)
0 - 30.0 ppm
(parts per mil-
lion)
0 - 20.00 ppm
(parts per mil-
lion)
0 - 20.00 ppm
(parts per mil-
lion)
0 - 100.00 ppm
(parts per mil-
lion)
Lower Detectable
Limit (LDL)
4 ppm 1.0 ppm 0.30 ppm 0.02 ppm 0.20 ppm
Reading
Increment
0.5 ppm 0.1 ppm 0.05 ppm 0.01 ppm 0.05 ppm
Warning
Setpoint
25 ppm 5.0 ppm 2.00 ppm 0.30 ppm 2.00 ppm
Alarm
Setpoint
35 ppm 10.0 ppm 4.00 ppm 0.60 ppm 5.00 ppm
Alarm H
Setpoint
300 ppm 30.0 ppm 20.00 ppm 0.60 ppm 100.00 ppm
Table 2: IR Sensor Specifications
Carbon Dioxide (CO2)

11 • Chapter 1: Introduction GX-3R Pro Operator’s Manual
STEL Setpoint 35 ppm 10.0 ppm 1.00 ppm 1.00 ppm 5.00 ppm
TWA Setpoint 25 ppm 4.7 ppm 0.50 ppm 0.30 ppm 2.00 ppm
Indication
Accuracy
± 10% of reading or ± 5% of full scale (whichever is greater)
Table 4: GX-3R Pro Specifications
Sampling
Method
Diffusion
Response Time T90 within 30 seconds
Display Graphics LCD Display
Max. Distance
for Bluetooth
Connection
30 feet, unobstructed
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
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)
Alkaline version not verified with CAN/CSA 60079-29-1 & ANSI/ISA 60079-29-1
C US
186718
Table 3: EC Sensor Specifications

GX-3R Pro Operator’s Manual Chapter 1: Introduction • 12
Power Supply
• Lithium ion battery pack (3.7 VDC, 200 mA)
OR
• Alkaline battery pack with 2 AAA batteries (3.0 VDC, 250 mA)
Continuous
Operating
Hours
@ 25 °C in
Measuring
Mode
(Non-Alarm
Operation)
Lithium Ion
Battery Pack
• Standard 4 gas + super-toxic EC: 25 hours (23 hours with
Bluetooth on)
• Super-toxic EC only: 50 hours
• Standard 4 gas + IR: 16 hours (15 hours with Bluetooth on)
• IR only: 24 hours
Alkaline Battery
Pack
• Standard 4 gas + super-toxic EC: 16 hours (14 hours with
Bluetooth on)
• Super-toxic EC only: 32 hours
• Standard 4 gas + IR: 7 hours (6 hours with Bluetooth on)
• IR only: 12 hours
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 (included with Li-ion versions only)
Other
Accessories
• 12 VDC charger
• 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
Lithium Ion Battery Pack Version
Approximately 65(H) x 73(W) x 26(D) mm (2.6”H x 2.9”W x 1.0”D)
Approximately 120 g (4.2 oz.)
Alkaline Battery Pack Version
Approximately 65(H) x 73(W) x 34(D) mm (2.6”H x 2.9”W x 1.3”D)
Approximately 140 g (4.9 oz.)
Table 4: GX-3R Pro Specifications

13 • Chapter 1: Introduction GX-3R Pro Operator’s Manual
About this Manual
The GX-3R Pro 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.

GX-3R Pro Operator’s Manual Chapter 2: Description • 14
Chapter 2: Description
Overview
This chapter describes the GX-3R Pro instrument and its accessories.
Instrument Description
Case
The GX-3R Pro’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
A digital LCD (liquid crystal display) is visible through a clear plastic window in the top case.
The LCD simultaneously shows the gas reading for all installed sensors. The LCD also shows
information for each of the GX-3R Pro’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 Pro
POWER
MODE
AIR
BackFront
LCD
Alarm
LEDs
Buzzer
Opening
Charging
Socket
Sensor
Retainer Bottom Cover
Threaded
Inserts
CO/H2S LEL O2TOXIC
Figure 1: Component Location

15 • Chapter 2: Description GX-3R Pro Operator’s Manual
Control Buttons
Two control buttons, AIR and POWER MODE are located below the LCD.
Alarm LEDs
Five sets of red alarm LEDs (light emitting diodes) around the edge of the case alert you to gas,
low battery, and failure alarms.
Buzzer
One solid-state electronic buzzer is located inside the case. Sound exits the case through a hole in
the middle front of the case. The buzzer sounds for gas alarms, malfunctions, low battery voltage,
and as an indicator during use of the GX-3R Pro’s many display and adjustment options.
Vibrator
A vibrating motor inside the GX-3R Pro case vibrates for gas alarms, unit malfunctions, and as an
indicator during normal use of the various modes of the GX-3R Pro.
NOTE: If STEALTH is set to ON, the vibrator only functions when VIBRATION in the
STEALTH Gas Select Mode item is set to ON. See “Stealth and Vibrator Settings
(STEALTH)” on page 196.
Button Function(s)
AIR • turns on LCD backlight
• resets alarm condition if LATCHING is set to ON in Maintenance
Mode
• enters User Mode, Maintenance Mode, and Gas Select Mode when
used with POWER MODE button
• activates the demand zero function (adjusts the GX-3R Pro’s fresh air
reading)
• changes the value of a parameter available for adjustment
• scrolls through parameter options
POWER MODE • turns the GX-3R Pro on and off
• turns on LCD backlight
• enters and scrolls through Display Mode
• enters instructions into the GX-3R Pro’s microprocessor
• resets alarm condition if LATCHING is set to ON in Maintenance
Mode
• enters User Mode, Maintenance Mode, and Gas Select Mode when
used with AIR button

GX-3R Pro Operator’s Manual Chapter 2: Description • 16
Sensors
The GX-3R Pro uses four sensors to monitor up to 5 gases simultaneously. The sensor retainer
and bottom cover hold the sensors in place. The sensors use different detection principles, as
described below.
Combustible Gas Sensor
The combustible gas sensor detects combustible gas in the % LEL range using 2 catalytic
elements: a standard element and a poison-resistant element that is resistant to sensor poisons like
silicone. The element’s resistance changes based on the reaction of gas with oxygen. The change
in resistance affects the current flowing through the element. The GX-3R Pro’s circuitry amplifies
the current, converts the current to a gas concentration, and displays the concentration on the
LCD.
The standard calibration for the combustible gas sensor is to methane but the sensor will still
detect and respond to a variety of combustible gases.
O2/CO/H2S/Super Toxic Sensors
The O2, CO, H2S, and super toxic sensors are electrochemical cells that consist of two precious
metal electrodes in a dilute 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 GX-3R Pro’s circuitry amplifies the
current, converts the current to a gas concentration, and displays the concentration on the LCD.
There are 4 different types of CO and H2S sensors available:
• CO only (ESR-A13P-CO): A single electrochemical cell that detects CO.
•H
2compensated CO (ESR-A1CP-CO-H): A single electrochemical cell that detects CO.
This sensor does not respond to or responds minimally to hydrogen (displays H2 RICH
once H2concentration reaches 2000 ppm).
•H
2S only (ESR-A13i-H2S): A single electrochemical cell that detects H2S.
•CO/H
2S (ESR-A1DR-COHS): A combination electrochemical cell that detects both CO
and H2S.
IR Sensors
The infrared sensors detect CO2in the ppm and % volume ranges. Gas enters the sensor through
an opening on its face. Infrared light shines through the gas and into an infrared detector. The
intensity of the infrared light changes with the gas concentration and this change is converted to
an electrical signal. The GX-3R Pro’s circuitry converts the signal into a gas concentration and
displays the gas concentration on the LCD.
Dummy Sensors
A dummy sensor is installed in any units that have less than 4 sensors. Dummy sensors are factory
installed. The flat side of the dummy sensor faces away from the GX-3R Pro and the hollow side
faces toward the GX-3R Pro.

17 • Chapter 2: Description GX-3R Pro Operator’s Manual
Filters
Combustible Gas Sensor H2S Removal Filter Disk (Dark Red)
An H2S removal filter disk is placed into a recess in the filter gasket over the combustible gas
sensor. The filter disk prolongs the life of the combustible gas sensor by preventing H2S in the
ambient air from reaching the sensor. The H2S filter disk is dark red in color and although it may
darken over time, its color is not indicative of remaining filter life.
The H2S filter disk needs replacing once it’s been exposed to 33 ppm hours of H2S. This means
the filter needs replacing after 80 minutes of exposure to 25 ppm H2S which equates to 40 2-
minute calibrations with a cylinder containing 25 ppm H2S. If H2S exists in the monitoring
environment, the H2S filter disk will have to be replaced more frequently.
CO/H2S Sensor Dual Filter (Black and White)
A dual filter is placed into a recess in the filter gasket over the dual CO/H2S sensor. The black half
is a charcoal filter for the CO sensor. The white half is a humidity filter for the H2S sensor.
Replace the filter if you notice:
• Unexplained CO readings.
• For users with a 1 ppm H2S alarm setpoint: A drift on the H2S zero reading, unexplained
H2S readings, the filter appears dirty, or every 6 months (whichever is sooner).
CO Sensor Charcoal Filter (Black)
A black charcoal filter is placed into a recess in the filter gasket over the CO sensor. The charcoal
filter disk scrubs H2S and certain hydrocarbons out of the sample to avoid false CO readings. If
false or elevated CO readings are noticed, especially in the presence of H2S, change the charcoal
filter.
H2S and PH3Sensors’ Humidity Filter (White)
A white humidity filter is placed into a recess in the filter gasket over the H2S or PH3sensor (if an
H2S or PH3sensor is installed). The filter absorbs humidity in the sampling environment to
prevent unstable readings around 0 ppm. “H2S” and “PH3” are printed on the side of the filter.
•H
2S: For users with a 1 ppm H2S alarm setpoint, the filter should be replaced every 6
months, if you notice a drift on the zero reading, or if the filter appears dirty (whichever is
sooner). For users with a 2 ppm or higher H2S alarm setpoint, the filter does not
necessarily ever need to be replaced.
•PH
3: The filter should be replaced every 6 months.
NO2and SO2Sensors’ H2S Removal Filter Disk (Tan)
An H2S removal filter disk is placed into a recess in the filter gasket over the NO2or SO2sensor
(if an NO2or SO2sensor is installed). The filter disk prolongs the life of the sensors by preventing
H2S in the ambient air from reaching the sensor. The filter should be replaced every 6 months.
HCN Sensor’s H2S Removal Filter Disk (Dark Gray)
An H2S removal filter disk is placed into a recess in the filter gasket over the HCN sensor (if an
HCN sensor is installed). The filter disk prolongs the life of the sensors by preventing H2S in the
ambient air from reaching the sensor. The filter should be replaced every 6 months.

GX-3R Pro Operator’s Manual Chapter 2: Description • 18
NH3Sensor’s Humidity Filter (White)
A white humidity filter is placed into a recess in the filter gasket over the NH3sensor (if an NH3
sensor is installed). The filter absorbs humidity in the sampling environment to prevent unstable
readings around 0 ppm. The filter should be replaced every 6 months. “NH3” is printed on the
side of the filter.
Hydrophobic Dust Filter
The oval-shaped hydrophobic dust filter is attached to the top of the filter gasket, covering the
sensor ports and the filters. The filter gasket and hydrophobic dust filter get replaced as a set.
NOTE: Some GX-3R Pros have a hydrophobic dust filter that is not attached to the filter gasket.
When replacing the hydrophobic dust filter on one of these GX-3R Pros, remove the
filter and the gasket and replace it with a filter gasket/hydrophobic dust filter assembly.
Infrared Communications Port
An infrared (IR) communications port is located on the top of the case, near the top LEDs.
Logged data transmits through the port in standard IrDA protocol. A computer’s infrared port or
an IrDA/USB cable connected to a USB port can be used to download data to the GX-3R Data
Logger Management Program. See the GX-3R Data Logger Management Program operator’s
manual for data logging and downloading instructions.
Battery Pack
The GX-3R Pro is either powered by a rechargeable lithium-ion (Li-ion) battery pack or an
alkaline battery pack with 2 AAA batteries (Duracell MN2400 or PC2400). Instruments with a Li-
ion battery pack have a charging socket on the back of the instrument. Instruments with an
alkaline battery pack have a cover that allows for battery replacement.
The battery icon in the upper right of the LCD shows remaining battery life. A low battery
warning activates when the GX-3R Pro detects a low battery voltage. The GX-3R Pro sounds a
dead battery alarm when battery voltage is too low for Measuring Mode.
NOTE: Use of batteries or battery chargers not specified by RKI Instruments, Inc. will
compromise the CSA classification and may void the warranty. See page 120 and page
121 for more information.
WARNING: To prevent ignition of a hazardous atmosphere, batteries must only be changed or
charged in an area known to be nonhazardous.
AVERTISSEMENT: Pour éviter l’inflammation d’une atmosphère dangereuse, les batteries
doivent uniquement être modifiés ou facturés dans une zone connue
comme non dangereuse.

19 • Chapter 2: Description GX-3R Pro Operator’s Manual
Included Accessories
Alligator Clip
An alligator clip is installed on the back of the GX-3R Pro. The alligator clip can be used to attach
the GX-3R Pro to clothing or a belt. Teeth in the alligator clip’s jaws prevent the unit from
slipping off. The alligator clip can be rotated to change the instrument’s orientation.
Rubber Boot
A black rubber boot is installed on the GX-3R Pro.
Wrist Strap
A wrist strap is included with the GX-3R Pro and can be attached to the wrist strap installation
feature on the left side of the GX-3R Pro’s case.
Single-Unit AC Charger
The charging cable is a 4 foot cable with an AC adapter on one end and a charging plug that
connects to the GX-3R Pro on the other end.
Figure 2: Alligator Clip
Alligator
Clip
Figure 3: Charging Cable
AC Adapter
Charging
Plug

GX-3R Pro Operator’s Manual Chapter 2: Description • 20
Calibration Cup
Use the calibration cup to apply gas during a bump test, calibration, or gas test. The calibration
cup has an installation orientation to observe. “Front” and “rear” imprinting on the bottom of the
cup correspond to the front and rear of the GX-3R Pro when the calibration cup is installed. In
addition, a “front” label on the front of the calibration cup should be visible when viewing the
LCD with the calibration cup installed.
Other Accessories
12 VDC Charger
The 12 VDC charger is a 4 foot cable with a vehicle plug on one end and a plug that connects to
the GX-3R’s power jack on the other end.
Multi-Unit Charger
The multi-unit charger is a 4 foot wall plug style adapter that plugs into a bar. The bar has five 2-
foot cables coming out one side. The end of each of the five cables has a plug that connects to the
GX-3R Pro’s power jack. The AC adapter is rated 100 - 240 VAC input, 5.99 VDC output.
Belt Clip
A belt clip makes it easy to hook the GX-3R Pro to a utility belt.
Figure 4: Calibration Cup
FRONT
Figure 5: Belt Clip
Belt Clip