Rki instruments Gx-3r User manual

www.rkiinstruments.com

GX-3R

Operator’s Manual

Part Number: 71-0477

Revision: P1

Released: 5/15/19

GX-3R 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.

Periodic calibration and maintenance of the gas

monitor is essential for proper operation and correct

readings. Please calibrate and maintain this

instrument regularly! Frequency of calibration

depends upon the type of use you have and the sensor

types. Typical calibration frequencies for most

applications are between 1 and 3 months, but can be

required more often or less often based on your usage.

GX-3R Operator’s Manual

Table of Contents

Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

About the GX-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Chapter 2: Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Instrument Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

LCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Control Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Alarm LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Buzzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Vibrator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Infrared Communications Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Charging Socket and Battery Pack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Included Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Alligator Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Rubber Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Wrist Strap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Single-Unit Charging Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Calibration Cup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Other Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Multi-Unit Charger. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Belt Clip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

SDM-3R. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

RP-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

IrDA Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Chapter 3: Measuring Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Turning On the GX-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Performing a Demand Zero . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Turning Off the GX-3R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Measuring Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Monitoring an Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Combustible Gas Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Alarm Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Responding to Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

GX-3R Operator’s Manual

Chapter 4: Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Tips for Using Display Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Peak Screen (PEAK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

STEL Screen (STEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

TWA Screen (TWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Changing the Combustible Gas Sensor’s Gas (LIST) . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Changing the User ID (USER ID) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Changing the Station ID (STN ID) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Last Successful Calibration Date (CAL DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Last Successful Bump Test Date (BUMP DATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Date, Time, and Temperature Screen (TEMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Viewing Alarm Settings Screen (ALARM--PT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 5: User Mode and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Entering User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Tips for Using User Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Performing a Bump Test (BUMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Setting Calibration Parameters (CAL SET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Setting Bump Test Parameters (BUMP SET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Alarm Settings (ALARM--PT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Updating the Lunch Break Setting (LUNCH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Setting the Confirmation Beep and Non-Compliance Indicator (BEEP) . . . . . . . . . . . . . 66

Updating the Backlight Time (BL TIME). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Turning the Key Tone On/Off (KEY TONE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Display Mode Items (DISP SET) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Zero Suppression (ZERO SUP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Zero Follower (ZERO.FLWR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Setting the Date/Time (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Turning the Password On/Off (PASSWORD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Viewing the ROM/SUM (ROM/SUM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Entering Measuring Mode (START) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Chapter 6: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

Recharging the Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Replacing the Buzzer Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Replacing the Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Replacing the Hydrophobic Dust Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Replacing a Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Chapter 7: General Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

GX-3R Operator’s Manual

Appendix A: Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Entering Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Tips for Using Maintenance Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Performing a Calibration (GAS CAL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Performing a Gas Test (GAS TEST). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Sensor/Battery Replacement Date (SEN DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Performing a Bump Test (BUMP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Setting Alarms to Latching or Self-Resetting (LATCHING) . . . . . . . . . . . . . . . . . . . . . . 89

Turning the Demand Zero Function On/Off (DEM ZERO) . . . . . . . . . . . . . . . . . . . . . . . 89

Turning the Auto Zero Function On/Off (AUTOZERO) . . . . . . . . . . . . . . . . . . . . . . . . . 90

Turning the ID Display Function On/Off (ID DISP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Turning the Zero Suppression On/Off (ZERO SUP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Turning the Zero Follower On/Off (ZERO.FLWR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

User Mode Zero Suppression (ZSUP.DISP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

User Mode Zero Follower (ZFLW.DISP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Setting the Date/Time (DATE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Turning the Password On/Off (PASSWORD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Viewing the ROM/SUM (ROM/SUM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Performing a Default (M.DEFAULT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Entering Measuring Mode (START) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Appendix B: Gas Select Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Entering Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Tips for Using Gas Select Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Changing the Gas Combination (GAS COMB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

Saving the Alarm Points (SET R AP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Turning Calibration Max Span On/Off (MAX SPAN) . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Stealth and Vibrator Settings (STEALTH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

LEL Definition (CHG LEL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Exiting Gas Select Mode (START). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

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%).

6 • Chapter 1: Introduction GX-3R 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 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

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” classification for Class I, Division I, Groups A, B, C, and D hazardous

atmosphere (pending)

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 Operator’s Manual Chapter 1: Introduction • 7

Specifications

Table 1: Standard Sensor Specifications/Alarm Points

Table 2: GX-3R Specifications

Combustible Gas,

Methane (CH4) Cali-

bration Standard*

Oxygen (O2)Hydrogen

Sulfide (H2S)

Carbon

Monoxide (CO)

Detection Range 0 - 100% LEL 0 - 25% volume 0 - 100.0 ppm 0 - 500 ppm

Service Range n/a 25.1 - 40% volume 100.1 - 200.0 ppm 501 - 2,000 ppm

Reading

Increment

1% LEL 0.1% volume 0.1 ppm 1 ppm

Warning

Factory Setting

10% LEL** 19.5% volume,

decreasing**

5.0 ppm** 25 ppm**

Alarm

Factory Setting

25% LEL 18.0% volume,

decreasing

30.0 ppm 50 ppm

Alarm H

Factory Setting

50% LEL 23.5% volume,

increasing

100.0 ppm 1200 ppm

STEL Alarm n/a n/a 5.0 ppm 200 ppm

TWA Alarm 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.

Sampling

Method

Diffusion

Response Time T90 within 30 seconds

Display Graphics LCD Display

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

Indication

Accuracy for

Detection

Range

Combustible Gas, Catalytic Type Sensor

• ± 5% of reading or ± 2% LEL (whichever is greater)

Oxygen

• ± 0.5% O2

Hydrogen Sulfide

• ± 5% of reading or ± 2 ppm H2S (whichever is greater)

Carbon Monoxide

• ± 5% of reading or ± 5 ppm CO (whichever is greater)

Indication

Accuracy for

Service Range

Oxygen

• ± 3.0% O2

Hydrogen Sulfide and Carbon Monoxide

• ± 20% of reading

8 • Chapter 1: Introduction GX-3R Operator’s Manual

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.

Safety/

Regulatory

• ATEX: II 1 G Ex da ia IIC T4 Ga

Certificate Number: DEKRA 17ATEX0103 X

• IECEx: Ex da ia IIC T4 Ga

Certificate Number: IECEx DEK 17.0050X

• CSA classified, “C/US”, as Intrinsically Safe. Exia. Class I, Groups A, B, C, & D.

Temperature Code T3A. (pending)

C US

186718

Power Supply Lithium ion battery pack

Continuous

Operating

Hours

@ 25 °C

25 hours in Measuring Mode (Non Alarm Operation, Fully Charged)

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 cable

Other

Accessories

• Multi-unit charger cable

• Belt clip

•SDM-3R

•RP-3R

• 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.)

GX-3R Operator’s Manual Chapter 2: Description • 9

Chapter 2: Description

Overview

This chapter describes the GX-3R instrument and its accessories.

Instrument Description

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 is located on the front of the case for viewing

the LCD. The black bottom cover is located on the bottom of the case and 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.

GX-3R

POWER

MODE

CO/H2SLELO2

AIR

Bottom

Cover

Charging

Socket

Sensor

Retainer

Buzzer

Opening Front Back

LCDLEDs

Threaded

Inserts

10 • Chapter 2: Description GX-3R Operator’s Manual

Control Buttons

Two control buttons, AIR and POWER MODE, are located below the LCD.

Alarm LEDs

The six alarm LEDs 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. A hole in the middle front of

the case allow the sound to exit the case. The buzzer sounds for gas alarms, malfunctions,

low battery voltage, and as an indicator during use of the 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. See “Stealth and Vibrator

Settings (STEALTH)” on page 102.

Sensors

The GX-3R uses three sensors to monitor combustible gas, oxygen (O2), carbon monoxide

(CO), and hydrogen sulfide (H2S) simultaneously. The sensors are located inside the

GX-3R and are held in their sockets by the sensor retainer and bottom cover. The sensors

use different detection principles, as described below.

Combustible Gas Sensor

The combustible gas sensor detects combustible gas in the %LEL range. It uses a catalytic

element for detection. 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 GX-3R’s circuitry, converted to a measurement of combustible gas

concentration, and displayed on the LCD.

Table 3: GX-3R Control Button Functions

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’s fresh air reading)

• changes the value of a parameter available for adjustment

• scrolls through parameter options

POWER MODE • turns the GX-3R on and off

• turns on LCD backlight

• enters and scrolls through Display Mode

• enters instructions into the GX-3R’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 Operator’s Manual Chapter 2: Description • 11

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 Sensors

The O2, CO, and H2S 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 current is amplified by the

GX-3R’s circuitry, converted to a measurement of gas concentration, and displayed on the

LCD.

There are 4 different types of CO and H2S sensors available:

• CO only (ESR-A13P): A single electrochemical cell that detects CO. Instruments with

this sensor cannot detect H2S.

•H

2 compensated CO (ESR-A1CP): A single electrochemical cell that detects CO. This

sensor does not respond to or responds minimally to hydrogen. Instruments with this

sensor cannot detect H2S.

•H

2S only (ESR-A13i): A single electrochemical cell that detects H2S. Instruments

with this sensor cannot detect CO.

•CO/H

2S (ESR-A1DR): A combination electrochemical cell that detects both CO and

H2S.

Dummy Sensors

Any unit that has less than 3 sensors will have a dummy sensor installed in one or more

unused sensor positions. Dummy sensors are factory installed. The flat side of the dummy

sensor should face away from the GX-3R and the hollow side should face toward the

GX-3R.

Filters

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. It prolongs the life of the sensor by preventing H2S in the ambient air from

reaching the combustible gas 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 can absorb H2S for 33 ppm hours and should be replaced after that

much exposure. With this many ppm hours of absorption, the H2S filter disk should be

replaced after 80 minutes of exposure to 25 ppm H2S. This equates to replacing the H2S

filter disk after 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.

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.

If your instrument has a combo CO/H2S sensor, it will have a filter installed that is half

12 • Chapter 2: Description GX-3R Operator’s Manual

black charcoal filter and half white humidity filter.

Humidity Filter (White)

A white humidity filter covers the H2S sensor.

If your instrument has a combo CO/H2S sensor, it will have a filter installed that is half

black charcoal filter and half white humidity filter.

Hydrophobic Dust Filter

The oval-shaped hydrophobic dust filter sits on the filter gasket, covering the sensor ports

and the filters.

Infrared Communications Port

An infrared (IR) communications port is located on the top of the case, near the top LEDs.

The data transmitted through the port is 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 saved

by the GX-3R to a computer using the GX-3R Data Logger Management Program. See the

GX-3R Data Logger Management Program operator’s manual for data logging and

downloading instructions.

Charging Socket and Battery Pack

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.

When the GX-3R detects a low battery voltage, a low battery warning is activated. When

battery voltage is too low for Measuring Mode, the GX-3R sounds a dead battery alarm.

The battery pack can be recharged by using the GX-3R charging cable. The battery pack is

not user-replaceable.

NOTE: Use of batteries or battery chargers not specified by RKI Instruments, Inc. will

compromise the CSA classification and may void the warranty. See

“Recharging the Batteries” on page 74.

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.

GX-3R Operator’s Manual Chapter 2: Description • 13

Included Accessories

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. The alligator clip can be rotated to change how the instrument is

oriented when worn.

Figure 2: Alligator Clip

Rubber Boot

A black rubber boot is installed on the GX-3R.

Wrist Strap

A wrist strap is included with the GX-3R and can be attached to the wrist strap installation

feature on the left side of the GX-3R’s case.

Single-Unit Charging Cable

The charging cable has an AC adapter on one end and a charging plug that connects to the

GX-3R on the other end.

Figure 3: Charging Cable

Alligator Clip

AC Adapter

Charging

Plug

14 • Chapter 2: Description GX-3R Operator’s Manual

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.

Figure 4: Calibration Cup

Other Accessories

Multi-Unit Charger

The multi-unit charger is a wall plug style adapter that plugs into a bar. The bar has five

4-foot cables coming out one side. The end of each of the five cables has a plug that

connects to the GX-3R’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 to a utility belt.

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.

RP-3R

The RP-3R is a pump that allows sample to be drawn to the GX-3R.

IrDA Cable

Unless your computer has a built-in IrDA port, an IrDA cable is needed to establish

communication between the GX-3R and the Datalogging Program or the User Setup

Program.

FRONT

GX-3R Operator’s Manual Chapter 3: Measuring Mode • 15

Chapter 3: Measuring Mode

Overview

This chapter explains how to use the GX-3R to perform confined space entry monitoring

or general area monitoring in Measuring Mode. Display Mode is accessed from

Measuring Mode by pressing POWER MODE and is described in “Chapter 4: Display

Mode” on page 29.

Start Up

This section explains how to start up the GX-3R, get it ready for operation, and turn it off.

NOTE: The screens illustrated in this section are for a standard 4-gas unit. The screens

displayed by your GX-3R may be slightly different.

Turning On the GX-3R

To illustrate certain functions, the following description of the GX-3R start up sequence

assumes that the following menu items in User Mode are turned on: LUNCH, CAL

RMDR, and BUMP.RMDR in User Mode, and ID DISP and AUTOZERO in

Maintenance Mode. If any of these items are turned off, then the corresponding screens

will not appear.

1 . Press and briefly hold down POWER MODE. Release the button when you hear a

beep.

2 . If LUNCH is set to ON (factory setting if OFF, see “Updating the Lunch Break

Setting (LUNCH)” on page 65), the Lunch Break Screen appears. The unit counts

down from 5 seconds.

a. Continue Accumulating: To continue accumulating peak and time-weighted

average (TWA) readings from the last time the GX-3R was used, press and

release POWER MODE or allow the countdown to reach 0. The short-term

exposure limit (STEL) reading is reset each time the GX-3R is turned on.

b. Reset Accumulation: To reset the accumulation of peak and time-weighted

average (TWA) readings, press and release AIR before the countdown reaches 0.

RESUME

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16 • Chapter 3: Measuring Mode GX-3R Operator’s Manual

3 . If CAL RMDR is set to ON (factory setting) and a calibration is due, the screen that

appears next depends on how CAL EXPD is set in User Mode (see “CAL EXPD” on

page 57). The three possible screens are described below. If a calibration is not due,

the instrument will tell you how many days are left until a calibration is due.

CAL EXPD set to

CONFIRM (factory setting)

CAL EXPD set to

CANT USE

CAL EXPD set to

NONE

LCD

Sound Buzzer sounds double pulsing tone Buzzer sounds double pulsing

tone

None

Action • Option A, Perform calibration:

Press and release POWER

MODE to enter User Mode to

perform a calibration. See

“Performing a Calibration (GAS

CAL)” on page 47 for

calibration instructions.

If the calibration was success-

ful, the screen above will not

appear again until the unit is due

for calibration. If the calibra-

tion was not successful, the

screen above will again appear

in the startup sequence.

• Option B, Bypass message: To

continue without performing a

calibration, press and release

AIR.

The GX-3R cannot be used until a

successful calibration has been

performed. Press and release

POWER MODE to enter User

Mode and perform a calibration.

See “Performing a Calibration

(GAS CAL)” on page 47 for cali-

bration instructions.

If the calibration was successful,

the screen above will not appear

again until the unit is due for cali-

bration. If the calibration was not

successful, the screen above will

again appear in the startup

sequence.

• Option A, Perform calibration:

If you want to enter User Mode

to perform a calibration, press

and release POWER MODE.

• Option B, Bypass message: To

continue without performing a

calibration, wait a few seconds

for the instrument to continue

with its startup sequence.

CAL--LMT

7:49

CAL

CAL--LMT

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FAIL

NEXT CAL

7:49

0 d

GX-3R Operator’s Manual Chapter 3: Measuring Mode • 17

4 . If BUMP.RMDR is set to ON (factory setting is OFF) and a bump test is due, the

screen that appears next depends on how BUMP.EXPD is set in User Mode (see

“BUMP.EXPD” on page 61). The three possible screens are described below. If a

bump test is not due, the instrument will tell you how many days are left until a bump

test is due.

5 . The Date/Time Screen appears for a few seconds.

BUMP.EXPD set to

CONFIRM (factory setting)

BUMP.EXPD set to

CANT USE

BUMP.EXPD set to

NONE

LCD

Sound Buzzer sounds double pulsing

tone

Buzzer sounds double pulsing tone None

Action • Option A, Perform bump test:

Press and release POWER

MODE to enter User Mode to

perform a bump test. See

“Performing a Bump Test

(BUMP)” on page 43 for bump

test instructions.

If the bump test was success-

ful, the screen above will not

appear again until the unit is

due for bump testing. If the

bump test was not successful,

the screen above will again

appear in the startup sequence.

• Option B, Bypass message: To

continue without performing a

bump test, press and release

AIR.

The GX-3R cannot be used until a

successful bump test has been per-

formed. Press and release POWER

MODE to enter User Mode and

perform a bump test. See “Per-

forming a Bump Test (BUMP)” on

page 43 for bump test instructions.

If the bump test was successful, the

screen above will not appear again

until the unit is due for bump test-

ing. If the bump test was not suc-

cessful, the screen above will again

appear in the startup sequence.

• Option A, Perform bump test:

If you want to enter User Mode

to perform a bump test, press

and release POWER MODE.

• Option B, Bypass message: To

continue without performing a

bump test, wait a few seconds

for the instrument to continue

with its startup sequence.

BUMP--LMT

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CAL

BUMP--LMT

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FAIL

NEXT BP

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18 • Chapter 3: Measuring Mode GX-3R Operator’s Manual

6 . The Battery Voltage Screen appears for a few seconds.

An “AL-L” at the bottom of the screen indicates that the alarms are set to latching.

An “AL-A” at the bottom of the screen indicates that the alarms are set to auto reset.

See “Setting Alarms to Latching or Self-Resetting (LATCHING)” on page 89 for a

description of how to change this parameter.

7 . The following screens display for 3 seconds each: the Gas Name Screen, the Full

Scale Screen, the Warning Setpoint Screen, the Alarm Setpoint Screen, the Alarm H

Setpoint Screen, the STEL Alarm Screen, and TWA Alarm Screen.

NOTE: If the combustible gas is set to something other than CH4 or H2 in Gas Select

Mode, the combustible channel is displayed as “HC” and the gas formula for

the combustible gas sensor’s target gas appears during startup.

AL - L V

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bAtt