INSTRUCTION MANUAL MODEL GX-86A PORTABLE FOUR GAS DETECTOR RKI Instruments, Inc.
Model GX-86A Instruction Manual INTRODUCTION The RKI Model GX-86A is an advanced gas detection instrument, incorporating proven detection hardware and microprocessor controls. The GX-86A is compact, convenient, and offers a full range of features, including: • Simultaneous detection of combustible gas, oxygen deficiency, carbon monoxide, and hydrogen sulfide. (Other toxic gases optional.
Model GX-86A Instruction Manual DESCRIPTION The RKI Model GX-86A detects combustible gas (LEL), oxygen deficiency (O2), carbon monoxide (CO), and hydrogen sulfide (H2S). See Table 1 for standard detection ranges for these gases. Gas detection features include distinctive alarms for dangerous gas concentrations, time-weighted averaging and short term exposure limit for toxic gases, and logging of detection data.
Model GX-86A Instruction Manual Internal Buzzer Control Panel Interface Port Battery Cover Remote Alarm/ Charger Jack Earphone Jack Sensor Cover Figure 1. GX-86A Components RKI Instruments, Inc.
Model GX-86A Instruction Manual COMPONENTS AND CONTROLS Case The GX-86A has a durable plastic case. The sensors are housed in a detachable block at the bottom of the instrument. Control Panel The control panel contains the display, alarm lights, and switches that control the many functions of the GX-86A. The switches are touchpads, to reduce the possibility of accidental activation or damage. See Figure 2. % LEL AIR ▲ PPM % (SHIFT) ▼ DISPLAY /(ADJ.) PPM ON/OFF /ENTER OFF - HOLD 5 SEC Figure 2.
Model GX-86A Instruction Manual 2. AIR/▲ The AIR/▲ switch activates the GX-86A’s Demand Zero function, which automatically adjusts the instrument in fresh-air conditions. It is also used to scroll through the display and settings modes. 3. (SHIFT)/▼ The (SHIFT)/▼ switch scrolls through the display and settings modes, and enters instructions into the GX-86A’s microprocessor. 4. DISPLAY/(ADJ) The DISPLAY/(ADJ) switch activates the display modes, and enters instructions into the GX-86A’s microprocessor. 5.
Model GX-86A Instruction Manual analysis programs. Buzzers and Earphone An electronic buzzer is mounted at the back of the case, behind a felt screen. The buzzer sounds for gas alarms and system malfunctions. A 2.5 mm phone jack at the bottom left rear corner of the case connects to an earphone, for use in high noise environments. An identical jack on the bottom right rear corner connects to an external buzzer or the optional battery charger.
Model GX-86A Instruction Manual atmosphere to diffuse inward. See Figure 3. H2S Sensor CO Sensor Spring Clips (2) Sensor Cover LEL Sensor O2 Sensor Figure 3. Sensors Combustible Gas Sensor The LEL sensor detects combustible gas and vapors in the atmosphere with a catalytic platinum element. The reaction of gas with oxygen on the catalyst causes a change in the resistance of the element, which is converted by the GX-86A into a reading of gas concentration.
Model GX-86A Instruction Manual atmosphere, producing a current proportional to the concentration of gas. The current is converted by the GX-86A into a measurement of gas concentration. The CO sensor uses a charcoal filter disk that covers its opening, to eliminate interference from H2S. To maintain sensitivity and stability, these sensors are kept on a continuous bias current, even when the instrument power is off. Batteries with an adequate charge must be installed to provide the bias current.
Model GX-86A Instruction Manual OPERATION Preparation Normally the GX-86A requires little preparation before use. To install the GX-86 Extender Cable, see the ACCESSORIES section. Standard Start-up 1. Press the ON/OFF/ENTER switch once. a.This message shows only when the “Lunchbreak” feature is activated (See USER OPTIONS). Press the AIR/▲ switch to continue Short Term Exposure Limit (STL) and Time-Weighted Average readings from the last use of the GX-86A. Press DISP/ (ADJ.
Model GX-86A Instruction Manual c. This message shows to verify that the data logger circuits are set properly for accurate data collection according to date and time. DATE / TIME MMM DD YY 00:00 d.These messages show while the GX-86A checks itself for proper operation. If a malfunction occurs, the display will alert the user. (The display shows “HC” [hydrocarbons] for the %LEL reading.) SELF DIAGNOSIS 10 SECONDS TO GO HC O2 H2S CO STANDBY d.
Model GX-86A Instruction Manual audible alarm will sound, the ALARM LED will blink, and the HC will flash on the display. RKI Instruments, Inc.
Model GX-86A Instruction Manual Caution Do not use gas from a cigarette lighter to test response to combustibles. Exposing the sensor to uncontrolled high concentrations of gas in this manner will reduce response and sensor life. WARNING IF THE GX-86A DOES NOT RESPOND TO THESE VERIFICATIONS, TAKE IT TO A KNOWN “FRESH-AIR” ENVIRONMENT, THEN FOLLOW THE DEMAND ZERO PROCEDURE DESCRIBED IN ADJUSTMENT AND CALIBRATION.
Model GX-86A Instruction Manual DISPLAY FUNCTIONS While the GX-86A is in normal operation, press the DISPLAY/(ADJ.) switch to step through the measurement functions. The display will hold for 20 seconds before reverting to normal detection, or until DISPLAY/(ADJ.) is pressed to go to the next screen. User and Station ID This screen appears only when the user ID option is activated. (See USER OPTIONS.) Use this screen to verify user, location, or other programmed information.
Model GX-86A Instruction Manual until a higher level is detected, the data logger is cleared, or the unit is turned off. HC O2 H2S CO P45 19.5 10.5 210 Average The Average function shows the average gas concentrations (indicated by “A” at the left side of the display) detected since the last time the GX-86A was turned on or the data logger was cleared. HC O2 H2S CO A18 20.8 2.5 100 Elapsed Time The Elapsed Time function shows the time in minutes since the memory was cleared or the instrument was turned on.
Model GX-86A Instruction Manual Time-Weighted Average (TWA) The TWA function shows the average reading for toxic gases during the last 8 hours. If 8 hours has not elapsed since the last time the STEL/TWA was cleared, the average is still calculated over 8 hours, with the missing time assigned a 0 value for readings. (TWA) H2S CO PPM XX.X XXX Battery Voltage The Battery Voltage function shows the minimum operating voltage and present battery voltage. BATTERY MIN. 2.3V BATTERY NOW 3.
Model GX-86A Instruction Manual Clear Data Logger The Clear Data Logger function allows the user to reset the data logger storage to accept a new set of data. Clearing the Data Logger also resets the Peak, Average, Time in Operation, STL, TWA, and Log. Time readings. This function shows three displays. Press AIR/▲ to continue through this function, or DISPLAY/(ADJ.) to skip to the next function. CLEAR DATALOGGER? YES: AIR NO: DISP ARE YOU SURE? YES:AIR NO:DISP CLEARED OK Log. Time The Log.
Model GX-86A Instruction Manual ALARMS Alarm Indications 1. Combustibles (%LEL) If the combustible gas detected exceeds the first level alarm setting (20% LEL for most applications), a pulsed tone will sound, the %LEL LED will blink, and the “HC” on the display will flash. If the combustible gas detected rises above the high alarm setting (50% LEL for most applications), the alarm tone and LED will be continuous. 2. Oxygen If the oxygen content of the air drops below the low alarm setting (usually 19.
Model GX-86A Instruction Manual 5. STEL (toxics only) If the average toxic gas level detected over the last 15 minutes exceeds the STL, an alarm will sound and the message “STL” will show on the display in the field for that gas. 6. TWA (toxics only) If the average toxic gas level detected over the last 8 hours exceeds the TWA, an alarm will sound and the message “TWA” will show on the display in the field for that gas. 7.
Model GX-86A Instruction Manual 1. Sensor failure If any sensor fails during operation, the display will show the failed sensor in parentheses (CO sensor in this example): SELF DIAGNOSIS FAIL( CO) To continue using the GX-86A, turn it off, then follow the appropriate start-up sequence. During start-up the display will show the failed channel before the count down. In normal operation display will indicate the failed sensor as “xx or xx.x.” HC O2 H2S CO 0 20.9 00.
Model GX-86A Instruction Manual CALIBRATION AND MAINTENANCE The GX-86A’s microprocessor circuits provide advanced calibration and adjustment features, including Demand Zero and Auto Calibration. Note Calibrate the GX-86A when a gas reading drifts below zero or a sensor has been replaced. Calibration Supplies and Equipment For automatic one-source calibration, the RKI Four Gas Cylinder can be used to adjust all sensors with one connection and one operation.
Model GX-86A Instruction Manual 3. Demand Zero Press and hold the AIR/▲ switch on the control panel until a tone sounds. Follow the instructions on the display: DEMAND ZERO HOLD AIR KEY ADJUSTING ZERO HOLD AIR KEY ZERO ADJUSTED RELEASE AIR KEY The instrument will automatically set the LEL and toxics circuits to zero and the O2 circuit to 20.9%. Calibration Start-up 1.
Model GX-86A Instruction Manual 2. Enter calibration mode With the instrument on, press and hold the (SHIFT)/▼ switch, then press the DISPLAY/(ADJ.) switch. The display will show: 1.AUTO CAL. 2.SET SPAN The “1” will flash, indicating the active selection. To select Auto Calibration, press ON/OFF/ENTER. (Go to next section, Auto Calibration.) To skip to separate calibration for individual sensors, press the (SHIFT)/▼ switch to scroll down through the calibration menu (Press AIR/▲ to scroll up).
Model GX-86A Instruction Manual Cylinder. AUTO CALIBRATION 50 12.0 25.0 50 To change the calibration values, press the (SHIFT)/▼ and DISPLAY/(ADJ.). The following screen will appear. SET CAL. 50 LEL Press the AIR/▲ or (SHIFT)/▼ to adjust the LEL value to agree with the concentration on the Four-Gas Cylinder. Press ON/OFF/ ENTER to advance to the SET CAL screen, the repeat the adjustment procedure for O2, H2S and CO. 2.
Model GX-86A Instruction Manual END screen will appear: AUTO CALIBRATION NORMAL END d.After the end screen, the display automatically returns to the first calibration screen. e Turn off the Four-Gas Cylinder and disconnect it from the valve. f. Press (SHIFT)/▼ to scroll through the options to “7.RETURN,” then press ON/OFF/ENTER to return to normal operation.
Model GX-86A Instruction Manual reading stabilizes: HC CAL. 45LEL GAS/ADJ./ENTER 3. If the reading does not correspond to the sample, press the AIR/▲ switch to increase the reading, or the (SHIFT)/▼ switch to decrease the reading. 4. Press ON/OFF/ENTER. The END screen will show: HC CAL. END 5. The display will automatically return to the Calibration Menu. Press (SHIFT) to scroll down to the next desired calibration. 6. Turn off the combustible gas cylinder and disconnect it from the valve. Oxygen Zero 1.
Model GX-86A Instruction Manual near the level of the low concentration sample. Adjust the reading using the AIR/▲ or (SHIFT)/▼ switches. 5. Press ON/OFF/ENTER to complete the oxygen zero sequence. 6. Turn off the zero oxygen cylinder and disconnect it from the valve.
Model GX-86A Instruction Manual H2S and CO Span 1. Connect a H2S or CO calibration cylinder to the adapter. 2. From the calibration menu, scroll to “4.SET SPAN ,” or “5.SET SPAN .” Press ON/OFF/ENTER to start the selected calibration. 3. Adjust the calibration value following the procedure in Combustibles Span, steps 2 - 6. Note The GX-86A will display up to 99 ppm H2S, but the limit of linear response is 60 ppm, well above acceptable exposure levels..
Model GX-86A Instruction Manual MAINTENANCE Batteries 1. Check the battery voltage periodically by pressing the DISPLAY switch to reach the Battery Voltage function. Replace the batteries before the voltage drops to the operational limit (see OperationAlarms). WARNING TAKE THE GX-86A TO A NON-HAZARDOUS LOCATION BEFORE CHANGING OR CHARGING THE BATTERIES. 2. To replace the batteries, remove the battery compartment cover.
Model GX-86A Instruction Manual Note If the batteries are fully discharged before replacement, allow 1/2 hour for the toxics circuits to show a normal response. Sensor Maintenance Electrochemical sensors (O2, H2S, CO) gradually deteriorate, regardless of use, and require periodic replacement. Combustibles sensor life is generally related to usage, but other factors may affect duration. The GX-86A sensors are easy to replace, but only the combustibles sensor contains user-serviceable components.
Model GX-86A Instruction Manual the start-up sequence and after the Demand Zero command. 3. The O2 reading tends to drift with instrument orientation. Toxics Sensors Replace the sensor when: 1. The detection circuit cannot be calibrated correctly. 2. The display does not show 0 (CO) or 00 (H2S) immediately after the start-up sequence and cannot be set to zero by Demand Zero. Note Allow up to 1/2 hour after the toxics sensors have been replaced to show a normal response, then calibrate. Sensor Replacement 1.
Model GX-86A Instruction Manual CO sensor with filter; do not use the filter with other other sensors. Sensor Block CO Sensor Filter (CO only) Rubber Collar (CO only) Figure 4. Sensor Installation 5. Insert a new sensor and turn clockwise. Be sure to use the correct socket for the sensor type; sensors are not interchangeable between sockets. 6. Reinstall the cover. 7. Turn on the instrument and verify the display is normal. 8. Calibrate the detection circuit to work correctly with the new sensor.
Model GX-86A Instruction Manual ACCESSORIES Extender Cable The Extender Cable extends the sensor block up to 10 meters from the instrument, allowing confined space and remote monitoring, with all the features of the GX-86A. The Extender cable includes the cable with sensor block plug and socket, and a rubber guard for the sensor cover. 1. Installing Extender Cable (Figure 5) Take the GX-86A to a non-hazardous area and turn off.
Model GX-86A Instruction Manual 6. Plug the sensor block into the end of the Extender Cable. Close the spring clips. 7. Slide the sensor cover over the block on the end of the Extender Cable. Slip on the rubber guard. 8. Start-up the GX-86A and verify operation as normal. RKI Instruments, Inc.
Model GX-86A Instruction Manual USER OPTIONS The advanced microprocessor program in the GX-86A allows the user to select and adjust many of the detection and data logging features. The GX-86A is pre-set to suit most applications; follow these instructions only if required. Entering Programming Mode 1. Take the GX-86A to a non-hazardous location—the instrument does not detect gas during programming operations. 2. Turn the GX-86A off. 3. Hold down the AIR and (SHIFT) switches, then press ON.
Model GX-86A Instruction Manual SET DEF. NVRAM 1. “DEF. SET ALL” The first option allows the user to reset all values for non-volatile RAM; all options are returned to default values. 2. “DEF. SET ALARM” The second option resets only the alarm levels to default values. 3. “DEF. SET O2 ZERO” The third option resets the O2 zero to default value. COMBINE GAS Sets the display and circuitry for types of gases to be detected; there are 11 possible combinations.
Model GX-86A Instruction Manual 3. “SET ALARM ” Prompts changes for LOW, TWA, STL, and CLG (ceiling) alarms for H2S. 4. “SET ALARM ” Prompts changes for LOW, TWA, STL, and CLG (ceiling) alarms for CO. SET SERIAL No. Sets the serial number for use by the Data Logger. 1. At the “SERIAL No.” screen, the first character (left end) will flash. Press AIR or SHIFT to scroll through 0 - 9, A - Z to select the desired character. 2. Press ON/OFF/ENTER to enter that value and move to the next character. 3.
Model GX-86A Instruction Manual SET INT. TIME Sets the interval between logging events for the Data Logger. Minimum value 10 seconds, maximum value 300 seconds. LATCHING ALARM Toggles the instrument alarm logic between self-resetting (default) and latching alarms. Note In the event of an alarm, the latching alarms option requires the user to press DISPLAY/(ADJ.) to reset the alarms, even after the gas concentration has dropped below the alarm level. SET LUNCH Toggles the Lunchbreak feature on and off.
Model GX-86A Instruction Manual SET LOG ALARM Sets the value of Data Logger memory capacity alerts on the GX-86A. Default setting is off, with a range of 1 - 100%. Tip: hold AIR or (SHIFT) to scroll rapidly through values. AUTO CAL. The procedure is the same as described in Calibration and Maintenance, Auto Calibration. DISPLAY VOL. Displays the output (in mV) for each of the active sensors. START Press ON/OFF/ENTER to begin the instrument’s normal start-up sequence.