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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 RKI Instruments, Inc. www.rkiinstruments.com...
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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. 2 • GX-3R Condensed Operator’s Manual...
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S 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. GX-3R Condensed Operator’s Manual • 5...
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...
TWA Setpoint 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...
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Table 2: GX-3R Specifications • 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...
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. GX-3R Condensed Operator’s Manual...
Figure 1: Component Location 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.
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GX-3R’s many display and adjustment options. Vibrator A vibrating motor inside the GX-3R case vibrates for gas alarms, unit malfunctions, and as an indicator during normal use of the various modes of the GX-3R. NOTE: If STEALTH is set to ON, the vibrator only functions when VIB in the STEALTH Gas Select Mode item is set to ON.
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Dummy Sensors A dummy sensor is installed in any units that have less than 3 sensors. Dummy sensors are factory installed. The flat side of the dummy sensor faces away from the GX-3R and the hollow side faces toward the GX-3R.
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A charging socket on the back of the instrument allows for charging cable connection. A lithium ion (Li-ion) battery pack powers the GX-3R. At 25°C the battery lasts at least 25 hours. The battery icon in the upper right of the LCD shows remaining battery life.
Alligator Clip An alligator clip is installed on the back of the GX-3R. The alligator clip can be used to attach the GX-3R to clothing or a belt. Teeth in the alligator clip’s jaws prevent the unit from slipping off.
Figure 4: Calibration Cup Other Accessories 12 VDC Charger The 12 VDC charger is a 4 foot cable with a vehicle plug on one end and plug that connects to the GX-3R’s power jack on the other end. Multi-Unit AC Charger The multi-unit charger is a 4 foot wall plug style adapter that plugs into a bar.
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SDM-3R The SDM-3R is a calibration station for the GX-3R and GX-3R Pro. The station’s buttons can be used for operations (Standalone Mode) or a computer can be used to control the docking station (PC Controlled Mode). See the appropriate SDM-3R manual for more information.
This chapter explains how to use the GX-3R to perform confined space entry monitoring or general area monitoring in Measuring Mode. Start Up This section explains how to start up the GX-3R, get it ready for operation, and turn it off. WARNING: A thin protective film covers the display to prevent scratches during shipping. Remove this film before use.
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• Option A, Perform calibration: • Option A, Perform calibration: Action The GX-3R cannot be used until a Press and release POWER To perform a calibration, press successful calibration is per- MODE to perform a calibration. and release POWER MODE.
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None • Option A, Perform bump test: • Option A, Perform bump test: To Action The GX-3R cannot be used until a Press and release POWER perform a bump test, press and successful bump test has been per- MODE to perform a bump test.
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Depending on the version, one of the following screens appears, the LEDs flash, and the instrument beeps. Press and release POWER MODE to confirm the HC Gas List screen and continue to the Gas Name Screen. If POWER MODE is not pressed after 5 seconds, the GX-3R will automatically proceed to the next screen. 7:49...
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9. If ID DISP is set to ON (factory setting is OFF, see page 88), the User ID Screen appears for a few seconds, followed by the Station ID Screen. 7:49 7:49 USEr Id Stn Id U_ID_001 S_ID_001 GX-3R Condensed Operator’s Manual Chapter 3: Operation • 21...
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10. If the GX-3R experiences a sensor failure during start up, the display shows which sensor failed and the buzzer sounds a double pulsing tone once per second. In the example below, the combustible gas sensor failed. 7:49 %LEL FAIL SENSOR Press and release POWER MODE to acknowledge the failure and continue.
(if KEY TONE is set to ON in User Mode). 4. Continue to hold AIR until the LCD prompts you to release it. The GX-3R sets the fresh air reading for all channels. Start up is complete and the unit is now ready for monitoring.
4. If Password Protection is turned On (factory setting is Off) using the SDM-3R PC program, a user- set password is required to turn off the GX-3R. When the password screen appears, adjust each digit with the AIR button and press and release the POWER MODE button to move on to the next digit.
OFF, the GX-3R gives periodic indications to confirm that it’s operating or to indicate a non- compliance (page 47). Monitoring an Area 1. Start up the GX-3R as described above in “Start Up” on page 17. It is now in Measuring Mode. 7:49 %LEL 20.9...
8. If you suspect that the GX-3R is not operating correctly: a. Take the GX-3R to a fresh air environment and perform a demand zero as described on page 23. b. Perform a bump test as described on page 51.
Overscale Protection The GX-3R protects the combustible gas sensor by temporarily turning off the sensor power if levels exceeding 100% LEL are detected. Nevertheless, combustible gas concentrations above 100% LEL can still affect the zero level or calibration of the combustible gas sensor.
1. Turn on the GX-3R as described on page 17. 2. Attach the sample cup to the GX-3R. Use the label and imprinting to make sure that the sample cup gets installed in the correct orientation relative to the GX-3R. Be sure the sample cup is pushed on all the way.
The GX-3R buzzer sounds an alarm, the LEDs flash, and the vibrator pulses when any sort of alarm condition or failure occurs. If the GX-3R is operating in Stealth Mode, the buzzer does not sound and the vibrator’s operation depend on the VIB setting in Gas Select Mode’s STEALTH menu item. See page 92 for more information.
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• Gas readings disappear. FAIL appears Double pulsing tone once in the middle of the screen and per second BATTERY appears at the bottom of the screen. • Alarm LEDs flash once per second 30 • Chapter 3: Operation GX-3R Condensed Operator’s Manual...
Buzzer silence is available for instruments with ROM version 07104 or newer. This feature can be turned on or off using the SDM-3R PC Controller program or the GX-3R Datalogging Program. Table 6 summarizes resetting and silencing alarms for all LATCHING and SILENCE setting combinations.
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Responding to Over Range Alarms WARNING: An over range condition may indicate an extreme combustible gas, toxic gas, or oxygen concentration. Confirm the gas concentration with a different GX-3R or with another gas detecting device. CAUTION: High off-scale readings may indicate an explosive concentration.
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“Recharging the Batteries” on page 73. The GX-3R is fully functional during a low battery warning. However, only 1-2 hours of operating time remain. The amount of operating time left depends on LCD backlight use and the alarm frequency.
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(see page 47). 2. Attempt to set the date using the DATE menu item in User Mode. See page 47. 3. If the date cannot be set correctly, contact RKI Instruments, Inc. as soon as possible. Responding to System Failure Alarms 1.
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Mode if the instrument must be used temporarily. CAUTION: There will be no datalogging function if you operate the instrument after a 031 system failure. Contact RKI Instruments, Inc. as soon as possible. GX-3R Condensed Operator’s Manual Chapter 3: Operation • 35...
The data logging capacity depends on how often the GX-3R stores data, how many channels are active, and how often the GX-3R is turned on and off. The table below illustrates how much data logging time is available for the various interval times. It assumes that the unit has three sensors, is only turned on once, and there are no alarm occurrences.
ON in Maintenance Mode (factory setting is OFF). Only appears if CAL RMDR is set to ON in User Mode (factory setting). Only appears if BUMP.RMDR is set to ON in User Mode (factory setting is OFF). GX-3R Condensed Operator’s Manual Chapter 4: Display Mode • 37...
GX-3R is turned off. The lunch break feature enables the GX-3R to save peak readings when it is turned off so it can continue with the same peaks when it is turned on again. See page 47 for instructions to turn the lunch break feature on (default is off).
TWA reading was cleared, the average is still calculated over 8 hours. The missing readings are assigned a 0 value. If LUNCH is set to OFF (factory setting), the TWA is cleared when the GX-3R is turned off.
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LIST screen. 5. The gas formula displays at the bottom of the Measuring Mode screen. The gas selection remains selected if you turn the instrument off and on again. GX-3R Condensed Operator’s Manual Chapter 4: Display Mode • 41...
The user ID provides a way to identify the GX-3R user during a data logging session. User IDs can only be selected in this menu item. In order to edit the 128 user IDs, you must use the GX-3R Datalogging Program.
Maintenance Mode is set to ON (factory setting is OFF). Use this screen to select a station ID from the 128 station IDs that are stored in the GX-3R’s memory. Before a station ID is selected on a brand new instrument, the station ID is “----------”. The factory- installed station IDs have a “S_ID_XXX”...
The BUMP DATA screen shows the date of each installed sensor’s last successful bump test. This screen only appears if BUMP.RMDR is set to ON. 1. After entering Display Mode, press and release POWER MODE until BUMP DATA appears. 7:49 dISP BUMP DATA 44 • Chapter 4: Display Mode GX-3R Condensed Operator’s Manual...
1. After entering Display Mode, press and release POWER MODE until ALARM--PT appears. 7:49 dISP ALARM--PT 2. Press and release AIR. The Full Scale Settings screen appears and shows full scale settings for each channel. GX-3R Condensed Operator’s Manual Chapter 4: Display Mode • 45...
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MODE at the same time to simulate the alarm conditions. The buzzer will sound, the LEDs will flash, and the instrument will vibrate just as it would if the displayed condition was actually happening. 5. Press and release POWER MODE to return to the Alarm Points Screen. 46 • Chapter 4: Display Mode GX-3R Condensed Operator’s Manual...
Overview This section describes the GX-3R in User Mode. See Table 11 below for a list of the items found in User Mode, the page that the menu item’s instructions can be found on, and a short description of the menu item.
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Return to the BUMP SET menu item in User Mode. ALARM-PT Set alarm points for all channels (WARNING, ALARM, ALARM H, STEL, TWA) or reset all alarms to their default settings. 48 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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CO: 2 ppm ZERO.FLWR ** ON (factory setting): Not intended for field adjustment. Oxygen channel does not support zero follower functionality. DATE Set the instrument’s date and time. GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 49...
The GX-3R is not in operation as a gas detector while in User Mode. 1. Take the GX-3R to a non-hazardous location and turn it off if it is on. 2. Press and hold AIR, then press and hold POWER MODE. When you hear a beep, release the buttons.
6. The BUMP menu item appears. 7:49 BUMP at the top of the screen indicates that the GX-3R is in User Mode. 8. Use AIR to move through the User Mode menu items. Tips for Using User Mode • To scroll from one menu item to the next, press and release AIR. To reverse the scrolling DIRECTION: a.
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2. Confirm that your cylinder selections are appropriate as described on page 67. 3. Install the calibration cup onto the GX-3R. Use the label and imprinting to make sure that the calibration cup gets installed in the correct orientation relative to the GX-3R. Be sure the calibration cup is pushed on all the way.
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Cylinder D but there is no reason to bump test the H response. 8. Make sure the GX-3R has been turned on for at least 45 seconds before continuing. 9. For toxic gas cylinders (like cylinders containing H S), it is important to vent the regulator while installing it onto the cylinder.
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Auto start after successful cal set to on? (default is on) *NOTE: Auto start after successful bump/cal parameters set using Datalogging or SDM-3R PC Programs. Figure 8: Bump Test Flow Chart 54 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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POWER MODE to go to the START item in the BUMP menu. 7. Remove the calibration cup. 8. Press and release POWER MODE to enter Measuring Mode. GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 55...
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11.9 7:49 6. Use AIR to scroll to START and press %LEL 11.9 and release POWER MODE to enter Measuring Mode. BUMP/ 7. Calibrate the GX-3R as soon as BUMP/ possible. 7:49 %LEL 7:49 %LEL /CAL 4. Close the regulator.
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7. Press and release POWER MODE to return to the START item in the BUMP enter Measuring Mode. menu. 8. Press and release POWER MODE to enter Measuring Mode. GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 57...
4. Press and release POWER MODE to enter the AIR CAL menu. 7:49 %LEL 20.9 AIR CAL 5. Make sure the GX-3R has been turned on for at least 45 seconds before continuing. 58 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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• Non-absorbent tubing • Calibration cup 1. Confirm that the GX-3R’s calibration gas values match the concentrations listed on the calibration gas cylinder(s) as described on page 65. 2. Confirm that your cylinder selections are appropriate as described on page 67.
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3. Install the calibration cup onto the GX-3R. Use the label and imprinting to make sure that the calibration cup gets installed in the correct orientation relative to the GX-3R. Be sure the calibration cup is pushed on all the way.
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CO sensor is installed, H is assigned to Cylinder D. 6. Make sure the GX-3R has been turned on for at least 45 seconds before continuing. 7. Press and release POWER MODE. 8. The gas readings flash and the bottom of the screen alternates between “APPLY” and “AUTO CAL”.
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Auto start after successful cal set to on? (default is on) *NOTE: Auto start after successful cal parameter set using Datalogging or SDM-3R PC Programs. Figure 10: Calibration Flow Chart 62 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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10. After the last cylinder is calibrated, the instrument continues to the START item in the AUTO CAL menu. 11. Remove the calibration cup. 12. Press and release POWER MODE to enter Measuring Mode. GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 63...
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7. Remove the calibration cup. 8. The instrument continues to the START item in the AUTO CAL menu. 9. Press and release POWER MODE to enter Measuring Mode. 64 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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4. Press and release POWER MODE. The Auto Cal screen for gases assigned to Cylinder A appears. 5. Use AIR to scroll to CAL--P. 7:49 CAL--P 6. Press and release POWER MODE. The combustible gas channel appears. 7:49 %LEL - - - CAL--P GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 65...
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CAL--P 7:49 ESCAPE 8. Press and release POWER MODE. The calibration value begins to flash. In the example below, the combustible gas channel is selected. 7:49 %LEL CAL--P 66 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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Cylinder D: CO). 1. While in User Mode, press AIR to scroll to GAS CAL. 7:49 GAS CAL 2. Press and release POWER MODE. The AIR CAL menu item appears. GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 67...
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5. Use AIR to scroll to CYL SEL. 7:49 CYL SEL 6. Press and release POWER MODE. The combustible gas channel displays. 7:49 %LEL - - - CYL SEL 68 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
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Menu. 14. Press AIR to scroll to ESCAPE. 15. Press and release POWER MODE. The instrument returns to the AUTO CAL menu item in the GAS CAL menu. GX-3R Condensed Operator’s Manual Chapter 5: User Mode and Calibration • 69...
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2. Press and release POWER MODE. The instrument returns to the GAS CAL menu item in User Mode. 3. Press AIR to scroll to START. 4. Press and release POWER MODE. The instrument begins its warmup sequence. 70 • Chapter 5: User Mode and Calibration GX-3R Condensed Operator’s Manual...
Chapter 6: Maintenance Overview This chapter describes troubleshooting procedures for the GX-3R. It also includes procedures for instrument cleaning, recharging the batteries, and replacing various consumable parts. WARNING: RKI Instruments, Inc. recommends that service, calibration, and repair of RKI Instruments be performed by personnel properly trained for this work. Replacing sensors and other parts with original equipment does not affect the intrinsic safety of the instrument.
0 - 40°C charging orange temperature range. temperature range. Instrument Cleaning Clean the GX-3R with a cloth dampened with water if it becomes excessively dirty. Do not use alcohol or other cleaning solvents. 72 • Chapter 6: Maintenance GX-3R Condensed Operator’s Manual...
LED turns on at the top of the GX-3R. Figure 11: Connecting the Charging Cable 4. The LED at the top of the GX-3R turns orange while charging. When a full charge has been reached, approximately 3 hours, the LED turns green.
5. Pull the charging jack straight out of the GX-3R’s charging socket. Figure 12: Removing the Charging Cable 6. Turn on the GX-3R and confirm that it starts up. Replacing the Buzzer Cover The buzzer cover may need to be replaced if it becomes saturated or clogged with particles.
Figure 13: Buzzer Cover Replacement 6. Reinstall the rubber boot. Replacing the Sensor Filters CAUTION: The buzzer cover, sensors, and filters are the only user-serviceable parts in the GX-3R. Do not replace or modify any other part. Combustible Gas Sensor Filter The H S filter disk is dark red in color and although it may darken over time, its color is not indicative of remaining filter life.
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H S scrubber disk. c. Black filter for CO-only sensor: The red side of the filter case should face toward the GX-3R. d. White filter for H S-only sensor: The white side of the filter case should face toward the GX-3R.
10. Reinstall the filter gasket/hydrophobic dust filter assembly onto the sensor retainer. The gasket tabs face down. 11. Reattach the bottom cover to the GX-3R. Push it onto the GX-3R until it snaps into place. 12. Reinstall the two screws that were loosened in Step 3.
8. Reattach the bottom cover to the GX-3R. Push it onto the GX-3R until it snaps into place. 9. Reinstall the two screws that were loosened in Step 3. Replacing a Sensor CAUTION: The CO and H S sensors contain an electrolyte solution. If contact with the electrolyte occurs, wash the area immediately.
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GX-3R. 9. Reinstall the filter gasket/sensor retainer assembly. The black and white filter goes over the CO/H sensor with the black half of the filter facing the edge of the GX-3R. Be sure the filter gasket/sensor retainer is oriented correctly.
CO and set the H response. Replacing the Battery Board Replace the battery board when the GX-3R doesn’t hold a charge anymore. 1. Verify that the GX-3R is off. 2. Remove the rubber boot, if installed.
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10. Place the new battery board battery-side-down in the rear case. The case has protrusions that fit in holes on the battery board. Side View Top View Black Gasket Rear Case Battery Board Figure 20: Reinstalling the Battery Board GX-3R Condensed Operator’s Manual Chapter 6: Maintenance • 81...
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Gasket, flat-side-up Figure 22: Reinstalling Battery Board Screws 13. Reinstall the rear case to the front case using the screws removed in Step 4. Figure 23: Removing Case Screws 82 • Chapter 6: Maintenance GX-3R Condensed Operator’s Manual...
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14. Reinstall the rubber boot, if being used. 15. Turn on the GX-3R. 16. If the instruments goes into a clock failure, set the date/time (see page 50). GX-3R Condensed Operator’s Manual Chapter 6: Maintenance • 83...
• The GX-3R draws a small amount of power even while it is shut off. A GX-3R with a full battery can be stored for 3 years without losing power. A GX-3R with a battery in low battery alarm can be stored for about 3 months without losing power.
USB A to USB mini cable, 6 feet, for 47-5084RK 47-5102 5 47-1019 charging cables with connector bar, no AC adapter 49-0133 Single-unit AC adapter, with 4 foot cable GX-3R Condensed Operator’s Manual Chapter 8: General Parts List • 85...
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Single-unit DC adapter, with 4 foot cable 57-2098 Replacement Li-ion battery with board 65-7004 Dummy sensor 71-0477 Operator’s Manual, GX-3R (this document) 71-0491 Operator’s Manual, GX-3R Datalogging Program 81-0000RK-51 Calibration cylinder, 200 ppm H in air, 34 liter steel 81-0090RK-01...
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Table 16: General Parts List (Continued) Part Number Description ESR-X13P-OXY Oxygen sensor NCR-6309 Combustible gas sensor, catalytic GX-3R Condensed Operator’s Manual Chapter 8: General Parts List • 87...
Appendix A: Maintenance Mode Overview This appendix describes the GX-3R in Maintenance Mode. The GX-3R is factory-set to suit most applications. Update settings in Maintenance Mode only if required for your specific application. Maintenance Mode items and their factory settings are listed in Table 17 below.
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OFF: You cannot manually perform a fresh air adjust in Measuring Mode by pressing AIR. AUTOZERO ON: The GX-3R asks if you want to perform a fresh air adjustment at the end of the startup sequence. OFF (factory setting): The GX-3R does not ask if you want to perform a fresh air adjust- ment at the end of the startup sequence.
The GX-3R is not in operation as a gas detector while in Maintenance Mode. 1. Take the GX-3R to a non-hazardous location and turn it off if it is on. 2. Press and hold AIR, then press and hold POWER MODE. You will hear a beep after one second.
Immediately press POWER MODE and then release both buttons. • To exit an entered menu item without saving a change, press and hold AIR and POWER MODE for a few seconds. GX-3R Condensed Operator’s Manual Appendix A: Maintenance Mode • 91...
Appendix B: Gas Select Mode Overview This appendix describes the GX-3R in Gas Select Mode. The GX-3R is factory-set to suit most applications. Update settings in Gas Select Mode only if required for your specific application. A description of the Gas Select Mode items is shown in Table 18 below.
7. The GAS COMB menu item displays. 7:49 GAS COMB at the top of the screen indicates that the GX-3R is in Gas Select Mode. 9. Use AIR to move through the Gas Select Mode menu items. Tips for Using Gas Select Mode •...
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Warranty RKI Instruments, Inc. warrants the GX-3R sold by us to be free from defects in materials, workmanship, and performance for a period of three 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.
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