RKI Instruments 65-2427RK-05 User manual

RKI Instruments, Inc.
www.rkiinstruments.com
65-2427RK-05
Hydrogen Sulfide Detector
Operator’s Manual
Part Number: 71-0227RK
Revision: C
Released: 6/15/20

2 • 65-2427RK-05 H2S Detector
WARNING
Read and understand this instruction manual before operating instru-
ment. 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.

65-2427RK-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 • 65-2427RK-05 H2S Detector
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
H2S Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Mounting the H2S Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Wiring the H2S Detector to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Replacing Components of the H2S Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Setting the Span Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

65-2427RK-05 H2S Detector • 5
Overview
This manual describes the 65-2427RK-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 65-2427RK-05, you must follow the instructions and warnings
in this manual to assure proper and safe operation of the 65-2427RK-05 and to
minimize the risk of personal injury. Be sure to maintain and periodically
calibrate the 65-2427RK-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
Detection Range 0 to 100 PPM (parts per million)
H2S Detector Signal Output 0.3 mA at 0 ppm H2S nominal
2.5 mA at 100 ppm H2S nominal
Response Time 90% in 30 seconds
Accuracy ± 5% of reading or ± 2 ppm H2S (whichever is greater)
Operating Temperature -40°F to 104°F (-40°C to 40°C)
!

6 • 65-2427RK-05 H2S Detector
Description
This section describes the components of the 65-2427RK-05 H2S detector. The 65-2427RK-
05 consists of the 65-2428 H2S detector and junction box.
Figure 1: H2S Detector Component Location
Rubber
Spacer,
3X
Terminal Block
H2S Detector
Red
Black
J-Box

65-2427RK-05 H2S Detector • 7
65-2428 H2S Detector
The 65-2428 H2S detector consists of the detector housing body, detector housing cap, cap
gasket, rubber boot, spacer, and the plug-in sensor.
Figure 2: H2S Detector Component Location
Detector Housing Body, Housing Cap, & Cap Gasket
The detector housing body protects the sensing components within the housing. Use the 3/4”
NPT mounting threads at the top of the housing to screw the H2S detector into the bottom
conduit hubs of the junction box. 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 body. Use these wires to connect the
H2S detector to the junction box terminal strip. 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

8 • 65-2427RK-05 H2S Detector
Plug-In 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 corresponds to the
detection range of the detector.
Junction Box
The junction box allows you to install the detector at a mounting site that is remote from a
controller, and it protects the detector wiring connections. Two conduit hubs allow you to
mount the detector to the junction box and connect the wiring from the detector to a controller.
Three spacers installed on the back of the junction box control the distance of the junction box
from a mounting surface and ensure that there is enough room to install a calibration cup on
the detector during calibration. The terminal block within the junction box facilitates the
wiring process. A cover on the front of the junction box allows access to the interior of the
junction box.
Installation
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. 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.

65-2427RK-05 H2S Detector • 9
Figure 3: Outline & Mounting Dimensions
2. At the monitoring site you select, hang or mount the junction box with the detector facing
down (see Figure 3).
Rubber
Spacers
3X
3.10
.75 .38
3.65
3/4 NPT
Female
H2S Detector
J-Box
1-1/2 - 20 Thread
for Calibration Cup
8.45 MAX

10 • 65-2427RK-05 H2S Detector
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. Remove the junction box cover.
WARNING: To maintain the explosion proof classification of the H2S detector, a conduit
seal must be used within 2 inches of the junction box conduit hub used for
wiring to the controller.
4. Guide a two-conductor, shielded cable or two wires in conduit through an unused conduit
hub of the junction box. Use appropriate conduit fittings and construction technique for
the environmental and hazardous location rating of the junction box. The junction box is
rated NEMA 4X and Class 1, Division 1, Groups B, C, D.
5. Connect the two wires to the detector using the 2 point 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.
6. Secure the junction box cover to the junction box.
7. Route the cable or wires leading from the H2S detector through one of the conduit hubs at
the controller housing. Use appropriate conduit fittings and construction technique for the
environmental rating of the controller. RKI controllers are typically rated NEMA 4X.
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.

65-2427RK-05 H2S Detector • 11
8. Connect the wires to the applicable controller terminal strip. See the controller operator’s
manual and the controller’s detector head specification sheet.
Figure 4: Wiring the H2S Detector to a Controller
9. If using shielded cable, connect the cable’s drain wire to an available chassis ground at the
controller. RKI controllers typically have a ground stud that is a convenient grounding
location.
10. Reinstall the junction box cover.
Cable Shield
+
H2S Detector
Red
Black
Terminal Block
Controller Detector/Transmitter
Terminals, Typical Designations
Controller Housing
S

12 • 65-2427RK-05 H2S Detector
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 power to the controller.
4. Turn on the controller.
5. 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 (Fresh Air) Reading”.
Setting the Zero (Fresh Air) Reading
WARNING: If the detector installation is explosion proof, do not remove the detector
housing cap or junction box cover while the circuits are energized unless the
area is determined to be non-hazardous. Keep the detector housing cap and
junction box cover tightly closed during operation.
CAUTION:If you suspect the presence of H2S in the monitoring environment, use the
calibration kit and a zero air calibration cylinder to introduce “fresh air” to the
H2S detector and verify an accurate zero setting. See “Calibration” on page 16
for instructions to introduce zero air to the H2S detector.
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.

65-2427RK-05 H2S Detector • 13
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 the Calibration section of this manual.
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.
Table 2: Troubleshooting the H2S Detector
Condition Symptom(s) Probable Causes Recommended Action
Fail
Condition
Controller indicates
a fail condition.
• The detector wiring is
disconnected or
misconnected.
• The plug-in sensor is
not properly plugged
into the sockets in the
detector housing body.
• The detector’s zero
reading is low enough
to cause a fail
condition.
• The detector is
malfunctioning.
1. Verify that the detector wiring is
correct and secure.
2. Confirm that the plug-in sensor is
installed properly.
3. Perform a zero adjustment. A full
calibration is recommended.
4. If the fail condition continues,
replace the plug-in sensor as
described later in this section.
5. If the fail condition continues,
contact RKI for further instruction.

14 • 65-2427RK-05 H2S Detector
Replacing Components of the H2S Detector
This section includes a procedure to replace the H2S sensor and the entire detector assembly.
In most cases, it is not necessary to replace the entire detector assembly.
Replacing the Plug-In H2S 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 body. Make sure not to lose
the cap gasket.
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.
Slow or No
Response/
Difficult or
Unable to
Calibrate
• Detector responds
slowly or does not
respond during
response test.
•Unable to
accurately set the
zero or response
reading during
calibration.
• Detector requires
frequent
calibration.
Note: Under
“normal”
circumstances, the
detector requires
calibration once
every 3 months.
Some applications
may require a more
frequent calibration
schedule.
• The calibration
cylinder is low, out-
dated, or defective.
• The flame arrestor in
the detector housing
cap is wet or clogged
with dirt or other
particulates.
• The calibration gas is
not an appropriate
concentration.
• The detector is
malfunctioning.
1. Verify that the calibration cylinder
contains an adequate supply of a
fresh test sample.
2. Check the detector housing cap to
determine if the flame arrestor is wet
or dirty. Clean if necessary.
3. Verify that the calibration gas
concentration is appropriate for the
detector. Zero emission air (20.9%
oxygen) is normally used for a zero
adjustment if the environment is
suspect and 25 PPM H2S in nitrogen
is normally used for a response
adjustment.
4. If the calibration/response difficulties
continue, replace the plug-in sensor
as described later in this section.
5. If the calibration/response difficulties
continue, contact RKI for further
instruction.
Condition Symptom(s) Probable Causes Recommended Action

65-2427RK-05 H2S Detector • 15
WARNING: The H2S sensor will not operate properly if the wire jumper is not removed.
7. Install the spacer and rubber boot onto the replacement sensor’s face.
8. Carefully plug the replacement sensor into the four-socket pattern that is located in the
detector housing.
9. Make sure the cap gasket is in place and screw the detector housing cap back onto the
detector housing body.
10. Turn on or plug in power to the controller.
11. Turn on the controller and place into normal operation.
CAUTION:Allow the replacement sensor to warm up for 5 minutes before you continue with
the next step.
12. Calibrate the replacement sensor as described in the Calibration section of this manual.
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 power to the controller.
3. Remove the junction box cover.
4. 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 junction box hub.
6. Guide the detector leads of the replacement detector through the junction box hub then
screw the mounting threads of the detector into the hub.
7. 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
to verify the connections are correct.
8. Reinstall the junction box cover.
Figure 5: Plug-In Sensor Jumper Removal
Remove jumper

16 • 65-2427RK-05 H2S Detector
9. Turn on or plug in power to the controller.
10. Turn on the controller and place into normal operation.
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 the Calibration section of this manual.
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 detector applications.
Unless experience in a particular application dictates otherwise, RKI Instruments, Inc.
recommends a calibration frequency of every 3 months for the H2S detector.
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
NOTE: Calibrating the H2S detector may cause alarms. Be sure to put the controller into its
calibration program or disable external alarms before calibrating.
WARNING: Do not remove the detector housing cap while the circuits are energized unless
the area is determined to be non-hazardous. Keep the detector housing cap
tightly closed during operation.
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 calibration kit sample tubing to connect the fixed flow regulator to the calibration
cup.

65-2427RK-05 H2S Detector • 17
4. Put the controller into its calibration program.
Setting the Zero Reading
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.
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.
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.
7. Leave the sample tubing connected to the regulator and the calibration cup.
NOTE: Depending on the size of your zero air cylinder, it is possible that you will have a
different regulator for the zero air cylinder and the H2S gas cylinder. If necessary to
fit the H2S calibration gas cylinder, change the regulator.
Setting the Span Reading
1. Follow the directions in the controller operator’s manual for setting the response reading
(span).
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 gas to flow for 2 minutes.
4. Set the response reading according to the controller operator’s manual.
5. After setting the response reading, turn the regulator’s on/off knob clockwise to close it.
6. Unscrew the regulator from the cylinder.
7. Remove the calibration cup from the detector.
NOTE: For convenience, leave regulator and calibration cup connected by the sample tubing.

18 • 65-2427RK-05 H2S Detector
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 to 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.
Parts List
Table 5 lists replacement parts and accessories for the H2S detector.
Table 3: Parts 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
18-0400RK-01 Junction box with rubber spacers
65-2427RK-05 H2S detector/j-box, CSA classified
65-2428 H2S detector (with plug-in sensor)
71-0227RK 65-2427RK-05 H2S Detector Operator’s Manual (this document)
81-0064RK-04 Calibration cylinder, 25 PPM H2S in nitrogen, 34 liter aluminum
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 cylinder, 25 PPM H2S in nitrogen, 58 liter
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