RKI Instruments 65-2423RK-05 User manual

www.rkiinstruments.com
65-2423RK-05
Hydrogen Sulfide Detector
Operator’s Manual
Part Number: 71-0126RK
Revision: B
Released: 7/6/20

2 • 65-2423RK-05 H2S Detector
WARNING
Read and understand this instruction manual before operating detec-
tor. Improper use of the detector could result in bodily harm or death.
Periodic calibration and maintenance of the detector is essential for
proper operation and correct readings. Please calibrate and maintain
this detector regularly! Frequency of calibration depends upon the
type of use you have and the sensor types. Typical calibration frequen-
cies for most applications are between 3 and 6 months, but can be
required more often or less often based on your usage.

65-2423RK-05 H2S Detector • 3
Product Warranty
RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in
materials, workmanship, and performance for a period of one year from date of shipment from
RKI Instruments, Inc. Any parts found defective within that period will be repaired or
replaced, at our option, free of charge. This warranty does not apply to those items which by
their nature are subject to deterioration or consumption in normal service, and which must be
cleaned, repaired, or replaced on a routine basis. Examples of such items are:
Warranty is voided by abuse including mechanical damage, alteration, rough handling, or
repair procedures not in accordance with the operator’s manual. This warranty indicates the
full extent of our liability, and we are not responsible for removal or replacement costs, local
repair costs, transportation costs, or contingent expenses incurred without our prior approval.
THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES
AND REPRESENTATIONS, EXPRESSED OR IMPLIED, AND ALL OTHER
OBLIGATIONS OR LIABILITIES ON THE PART OF RKI INSTRUMENTS, INC.
INCLUDING BUT NOT LIMITED TO, THE WARRANTY OF MERCHANTABILITY OR
FITNESS FOR APARTICULAR PURPOSE. IN NO EVENT SHALL RKI INSTRUMENTS,
INC. BE LIABLE FOR INDIRECT, INCIDENTAL, OR CONSEQUENTIAL LOSS OR
DAMAGE OF ANY KIND CONNECTED WITH THE USE OF ITS PRODUCTS OR
FAILURE OF ITS PRODUCTS TO FUNCTION OR OPERATE PROPERLY.
This warranty covers instruments and parts sold to users by authorized distributors, dealers,
and representatives as appointed by RKI Instruments, Inc.
We do not assume indemnification for any accident or damage caused by the operation of this
gas monitor, and our warranty is limited to the replacement of parts or our complete goods.
a) Absorbent cartridges d) Batteries
b) Pump diaphragms and valves e) Filter elements
c) Fuses

4 • 65-2423RK-05 H2S Detector
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Detector Housing, Housing Cap, & Cap Gasket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Rubber Boot and Spacer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Mounting the H2S Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Wiring the H2S Detector to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Preventive Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Replacing Components of the H2S Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Setting the Response Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

65-2423RK-05 H2S Detector • 5
Overview
This manual describes the 65-2423RK-05 hydrogen sulfide (H2S) detector. This manual also
describes how to install, start up, maintain, and calibrate the detector when it is used with a
gas monitoring controller. A parts list at the end of this manual lists replacement parts and
accessories for the H2S detector.
Specifications
WARNING: Do not use this product in a manner not specified in this instruction manual.
Table 1 lists specifications for the H2S detector.
NOTE: The following symbol on the detector label is a caution to the user to refer to this
documentation for installation and operation instructions:
WARNING: When using the 65-2423RK-05, you must follow the instructions and warnings
in this manual to assure proper and safe operation of the 65-2423RK-05 and to
minimize the risk of personal injury. Be sure to maintain and periodically
calibrate the 65-2423RK-05 as described in this manual.
Table 1: Specifications
Target Gas Hydrogen sulfide (H2S)
Area Classification* Explosionproof for Class I, Groups B, C, and D
Temperature Code T6
Installation Category Installation Category 1. Signal level, special equipment or parts
of equipment, telecommunication, electronic, etc., with smaller
transient overvoltages than Installation Category (Overvoltage
Category) II (ref. IEC 664).
Sampling Method Diffusion
H2S Detector Signal Output 0.3 mA at 0 ppm H2S nominal
2.5 mA at 100 ppm H2S nominal
Detection Range 0 to 100 PPM (parts per million)
Accuracy ± 5% of reading or ± 2 ppm H2S (whichever is greater)
Response Time 90% in 30 seconds
Operating Temperature -40°F to 104°F (-40°C to 40°C)
* The area classification only applies if the detector is installed using a junction box with an
internalvolume less than or equal to 69 cubic inches and rated explosion proof for Class I,
Groups B, C, and D. The detector is not explosion proof if it is installed in a non-explosion proof
enclosure, such as in a conduit hub of a controller like the Beacon 200 or Beacon 800.
!

6 • 65-2423RK-05 H2S Detector
Description
This section describes the components of the H2S detector. The detector consists of the
detector housing body, housing cap, cap gasket, rubber boot, spacer, and the H2S sensor.
Figure 1: H2S Detector Component Location
Detector Housing Body, Housing Cap, & Cap Gasket
The detector housing body protects the sensing components within the housing. Use the
mounting threads at the top of the housing to screw the H2S detector into a 3/4 NPT hub. Use
the removable cap near the bottom of the housing to access the sensor for maintenance or
replacement. The cap protects the sensor from damage and includes a flame arrestor which
contains any sparks which may occur within the detector housing. A cap gasket seals the
interface between the housing and cap. A flame arrestor guard is permanently bonded to the
cap.
Two wires extend from the top of the detector housing. Use these wires to connect the H2S
detector to a controller. The housing includes a four-socket pattern. This socket pattern
accepts the sensor’s four pins to secure the sensor within the detector housing. A pre-
amplifier, located between the sockets and two interconnect wires, conditions the sensor’s
signal before the signal reaches the controller.
Rubber Boot and Spacer
A rubber boot and spacer are installed between the detector housing cap and the sensor. They
help ensure that the detector remains plugged into the detector housing body.
Spacer
Rubber Boot
H2S Plug-inSensor
Flame
Arrestor
Guard
Detector
Housing Cap
Detector Housing Body
Cap Gasket

65-2423RK-05 H2S Detector • 7
Sensor
The sensor is secured within the sensor housing by four pins. Through a series of chemical
and electrical reactions, the sensor produces an electrical output that is proportional to the
detection range of the detector.
Installation
NOTE: Normally, the H2S detector is shipped already installed in one of the bottom conduit
hubs of a controller and factory wired to the controller. If your detector is already
installed in a controller, use this section for reference only.
This section describes procedures to mount the H2S detector in the monitoring environment
and wire the detector to a controller.
Mounting the H2S Detector
1. Whether you will mount the detector directly to a controller or to a junction box, select a
mounting site that is representative of the monitoring environment. Consider the following
when you select the mounting site.
• Select a site where the detector is not likely to be bumped or disturbed. Make sure
there is sufficient room to perform start-up, maintenance, and calibration procedures.
• Select a site where the target gas is likely to be found first.
NOTE: If your application does not require a specific mounting site, mount the detector at
approximately breathing level.

8 • 65-2423RK-05 H2S Detector
Figure 2: Outline & Mounting Dimensions
2. At the monitoring site, mount the detector in one of the following two ways:
• Screw the detector’s 3/4 NPT mounting thread into an empty conduit hub on a
controller.
OR
• Screw the detector’s 3/4 NPT mounting thread into an appropriately rated junction
box.
CAUTION: Mount the H2S detector with the detector facing down (see Figure 2).
NOTE: If the mounting site requires the detector installation to be explosion proof, you must
install the detector in a junction box with an internal volume less than or equal to 69
cubic inches and rated explosion proof for Class I, Groups B, C, and D.
Shrink Tubing
3/4 NPT
1.62 Flats for
Wrench
1-1/2-20 For Calibration Cup
9.75 Ref
2.25 Ref
Ø1.75
0.75
3.59

65-2423RK-05 H2S Detector • 9
Wiring the H2S Detector to a Controller
WARNING: Always verify that the power source is OFF before you make wiring
connections.
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. If the detector is mounted remotely from a controller using an explosion proof junction
box, proceed to step 4.
If the detector is mounted directly to a controller, connect the detector’s red and black
wires to the appropriate controller detector terminals and skip to the Startup Section.
4. Remove the junction box cover.
WARNING: To maintain the explosion proof classification of the H2S detector/junction box
combination, a conduit seal must be used within 2 inches of the junction box
conduit hub used for wiring to the controller. Adhere to your local electrical
code when installing the conduit seal.
5. Guide a two-conductor, shielded cable or two wires in conduit through an unused conduit
hub of the junction box.
6. Connect the two wires to the detector using an appropriate terminal block.
CAUTION: If using shielded cable, leave the drain wire insulated and disconnected at the
detector. You will connect the opposite end of the cable’s drain wire at the
controller.
7. Secure the junction box cover to the junction box.
8. Route the cable or wires leading from the H2S detector through one of the conduit hubs at
the controller housing.
CAUTION: Do not route power and detector wiring through the same conduit hub. The
power cable may disrupt the transmission of the detector signal to the controller.
9. Connect the wires to the applicable controller terminal strip. See the controller operator’s
manual and the controller’s detector head specification sheet for the H2S detector.
WARNING: If the controller’s construction is not explosion-proof, the controller must be
installed in an ordinary location. Do non install a non-explosion-proof
controller in a classified location.

10 • 65-2423RK-05 H2S Detector
.
Figure 3: Wiring the H2S Detector to a Controller
10. If shielded cable is used, connect the cable’s drain wire to an available chassis (earth)
ground at the controller. RKI controllers typically have a ground stud that can be used to
ground the cable’s drain wire.
11. Reinstall the junction box cover.
S
+
Controller H2S DetectorTerminals
(typical terminal designation shown)
RedBlack

65-2423RK-05 H2S Detector • 11
Start Up
This section describes procedures to start up the H2S detector and place the detector into
normal operation.
Introducing Incoming Power
1. Complete the installation procedures described earlier in this manual.
2. Verify that the power wiring to the controller is correct and secure. Refer to the controller
operator’s manual.
3. Turn on or plug in the incoming power at the power source end, then turn on the controller.
4. Verify that the controller is on and operating properly. Refer to the controller operator’s
manual.
CAUTION: Allow the detector to warm up for 5 minutes before you continue with the next
section, “Setting the Zero Signal”.
Setting the Zero Signal
WARNING: If the detector installation is explosion proof, do not remove the sensor cap or
junction box cover while the circuits are energized unless the area is
determined to be non-hazardous. Keep the sensor cap and junction box cover
tightly closed during operation.
CAUTION: If you suspect the presence of the target gas in the monitoring environment, use
the calibration kit and the zero air calibration cylinder to introduce “fresh air”
to the sensor and verify an accurate zero setting.
1. Verify that the detector is in a fresh air environment (environment known to be free of
hydrogen sulfide, other toxic and combustible gases, and of normal oxygen content,
20.9%).
2. Verify a reading of 0 ppm H2S at the controller.
If the display reading is 0 ppm H2S, start up is complete. The detector is in normal
operation. If the display reading is not 0 ppm H2S, continue with step 3.
3. Perform a zeroing operation at the controller. See the controller operator’s manual for
directions.

12 • 65-2423RK-05 H2S Detector
Maintenance
This section describes maintenance procedures. It includes preventive maintenance,
troubleshooting, and component replacement procedures.
Preventive Maintenance
This section describes a preventive maintenance schedule to ensure the optimum performance
of the H2S detector. It includes daily and quarterly procedures.
Daily
Verify a display reading of 0 PPM H2S at the controller. Investigate significant changes in the
display reading.
Quarterly
Calibrate the H2S detector as described in “Calibration” on page 15.
Troubleshooting
The troubleshooting guide describes symptoms, probable causes, and recommended action for
problems you may encounter with the H2S detector.
NOTE: This troubleshooting guide describes detector problems only. See the controller
operator’s manual for problems you may encounter with the controller.
Fail Condition
Symptoms
• The controller indicates a fail condition.
Probable causes
• The detector wiring is disconnected or misconnected.
• The detector’s zero reading is low enough to cause a fail condition.
• The detector is malfunctioning.
Recommended action
• Verify that the detector wiring is correct and secure.
• Calibrate the detector.
• If the fail condition continues, replace the H2S sensor as described later in this section.
• If the fail condition continues, contact RKI for further instruction.
Slow or No Response/Difficult or Unable to Calibrate
Symptoms
• Unable to accurately set the zero or response reading during the calibration procedure.
• The detector requires frequent calibration.

65-2423RK-05 H2S Detector • 13
NOTE: Under “normal” circumstances, the detector requires calibration once every three
months. Some applications may require a more frequent calibration schedule.
Probable causes
• The calibration cylinder is low, out-dated, or defective.
• The detector is malfunctioning.
Recommended action
1. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.
2. If the calibration/response difficulties continue, replace the H2S sensor as described later
in this section.
3. If the calibration/response difficulties continue, contact RKI Instruments, Inc. for further
instruction.
Replacing Components of the H2S Detector
This section includes a procedure to replace the H2S sensor and one to replace the entire
detector assembly. In most cases, it is not necessary to replace the entire detector assembly.
Replacing the Sensor
CAUTION: The sensor contains electrolyte which is a dilute acid. Do not disassemble the
sensor when replacing it with a new one. If sensor electrolyte comes in contact
with your skin, wash affected area thoroughly with soap and water.
1. Turn off the controller.
2. Turn off or unplug power to the controller.
3. Unscrew the detector housing cap from the detector housing.
4. Unplug and remove the H2S sensor with the rubber boot and spacer attached.
5. Remove the rubber boot and spacer from the old sensor.
6. Remove the replacement sensor from its packaging and remove the wire jumper. This wire
jumper is installed on the sensor pins for shipment or storage but must be removed for the
sensor to operate properly when installed in a detector.
WARNING: The H2S sensor will not operate properly if the wire jumper is not removed.
Figure 5: Plug-In Sensor Jumper Removal
Remove jumper

14 • 65-2423RK-05 H2S Detector
7. Install the spacer and rubber boot onto the replacement sensor’s face.
8. Carefully plug the replacement sensor into the socket pattern that is located in the detector
housing.
NOTE: Match the sensor’s male pins with the four female sockets as you plug the sensor into
the sockets.
9. Screw the detector housing cap onto the top section.
10. Turn on power to the controller.
11. Turn on the controller.
CAUTION: Allow the replacement sensor to warm up for 5 minutes before you continue with
the next step.
12. Calibrate the detector as described in “Calibration” on page 15.
Replacing the H2S Detector
NOTE: In most cases, it is only necessary to replace the H2S sensor.
1. Turn off the controller.
2. Turn off or unplug incoming power to the controller.
3. If the detector is installed directly on a controller, open the controller door.
If the detector is installed remotely from a controller in a junction box, remove the
junction box cover.
4. If the detector is installed directly on a controller, disconnect the detector leads from the
detector terminal strip in the controller. Note the position of the color-coded leads as you
remove them.
If the detector is installed remotely from a controller in a junction box, disconnect the
detector leads from the terminal block in the junction box. Note the position of the color-
coded leads as you remove them.
5. Unscrew the detector from the controller conduit hub or junction box hub.
6. Guide the detector leads of the replacement detector through the controller conduit hub or
junction box hub then screw the mounting threads of the detector into the hub.
7. If the detector is installed directly on a controller, connect the detector leads to the
appropriate detector terminal strip terminals. See the controller operator’s manual and the
controller’s detector head specification sheet for the H2S detector.
If the detector is installed remotely from a controller in a junction box, connect the
detector leads to the terminal block the same way the old detector was wired. See the
controller operator’s manual and the controller’s detector head specification sheet for the

65-2423RK-05 H2S Detector • 15
H2S detector to verify the connections are correct.
8. If the detector is installed remotely from a controller in a junction box, reinstall the
junction box cover.
9. Turn on or plug in power to the controller.
10. Turn on the controller.
CAUTION: Allow the replacement detector to warm up for 5 minutes before you continue
with the next step.
11. Calibrate the replacement detector as described in “Calibration” on page 15.
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a
calibration frequency of every 3 months is adequate for most H2S transmitter applications.
Unless experience in a particular application dictates otherwise, RKI Instruments, Inc.
recommends a calibration frequency of every 3 months for the H2S transmitter.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment, and calibration adjustments are minimal at calibration, then a
calibration frequency of every 6 months is adequate.
If an application is very demanding, for example if the environment is not well controlled,
then more frequent calibration than every 3 months may be necessary.
Calibration
This section describes how to calibrate the H2S detector. It includes procedures to prepare for
calibration, set the zero reading, set the response reading, and return to normal operation. It
describes calibration using a calibration kit that includes a calibration cup, calibration gas,
sample tubing, and a fixed flow regulator with an on/off knob. RKI Instruments, Inc.
recommends using a 0.5 LPM (liters per minute) fixed flow regulator.
Preparing for Calibration
1. Screw the calibration cup onto the bottom of the H2S detector.
2. Screw the regulator into the zero air calibration cylinder.
3. Use the sample tubing to connect the regulator to the calibration cup.
NOTE: If you can verify that the H2S detector is in a fresh air environment, you do not need
to apply zero air to the detector before adjusting the zero reading.
4. Put the controller into its calibration program.

16 • 65-2423RK-05 H2S Detector
Setting the Zero Reading
1. Follow the directions in the controller operator’s manual for setting the zero reading.
2. When the instructions call for applying zero air to the detector, turn the regulator’s on/off
knob counterclockwise to open it. Gas will begin to flow.
3. Allow the gas to flow for two minutes.
4. Set the zero reading according to the controller operator’s manual.
5. Turn the regulator’s on/off knob clockwise to close it.
6. Unscrew the regulator from the zero air calibration cylinder. Leave the sample tubing
connected to the regulator and the calibration cup.
Setting the Response Reading
1. Follow the directions in the controller operator’s manual for setting the response reading.
2. For toxic gas cylinders (like H2S), it is important to vent the regulator while installing it
onto the cylinder. Venting the regulator during installation helps prevent air from getting
into the cylinder and degrading the gas. When the directions call for exposing the detector
to gas, open the regulator by turning the knob counterclockwise and then install it onto the
cylinder.
3. Allow the gas to flow to the detector for 2 minutes.
4. Set the response reading according to the controller operator’s manual.
5. After setting the response reading, unscrew the regulator from the cylinder and remove the
calibration cup from the detector.
NOTE: For convenience, leave the regulator and calibration cup connected by the sample
tubing.
Returning to Normal Operation
1. Allow about 45 seconds for the gas reading to decrease below the alarm points and then
return the controller to normal operation.
NOTE: If you do not allow the gas reading decrease below the alarm points, then unwanted
alarms may occur.
2. Verify that the controller display reading decreases and stabilizes at 0 ppm H2S.
3. Store the components of the calibration kit in a safe and convenient place.

65-2423RK-05 H2S Detector • 17
Parts List
Table 2 lists replacement parts and accessories for the H2S detector.
Table 2: Pa rts List
Part Number Description
06-1248RK Sample tubing (order by the foot)
07-0033RK Detector housing cap gasket
07-0203RK Rubber retaining boot
14-2101RK Spacer between sensor and rubber boot
65-2423RK-05 H2S replacement detector assembly (includes sensor)
71-0126RK 65-2423RK-05 H2S Detector Operator’s Manual (this document)
81-0076RK Zero air calibration cylinder, 17 liter
81-0076RK-01 Zero air calibration cylinder, 34 liter steel
81-0076RK-03 Zero air calibration cylinder, 103 liter
81-0151RK-02 Calibration gas cylinder, 25 ppm H2S in nitrogen, 58 liter
81-0151RK-04 Calibration cylinder, 25 PPM H2S in nitrogen, 34 liter aluminum
81-1050RK Regulator with gauge and knob, 0.5 LPM, for 17 liter and 34 liter steel calibra-
tion cylinders (cylinders with external threads)
81-1051RK Regulator with gauge and knob, 0.5 LPM, for 34 liter aluminum, 58 liter, and
103 liter calibration cylinders (cylinders with internal threads)
81-1117RK Calibration cup
ES-1537-H2S H2S replacement sensor