RKI Instruments 65-2422RK-05 User manual

www.rkiinstruments.com
65-2422RK-05
Hydrogen Sulfide Transmitter
Operator’s Manual
Part Number: 71-0114RK
Revision: D
Released: 6/12/20

2 • 65-2422RK-05 H2S Transmitter
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.

65-2422RK-05 H2S Transmitter • 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 • 65-2422RK-05 H2S Transmitter
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
H2S Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Mounting the H2S Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Wiring the H2S Transmitter to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Preventive Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Replacing Components of the H2S Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Setting the Response Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

65-2422RK-05 H2S Transmitter • 5
Overview
This manual describes the hydrogen sulfide (H2S) transmitter. This manual also describes how
to install, start up, maintain, and calibrate the transmitter. A parts list at the end of this manual
lists replacement parts and accessories for the H2S transmitter.
Specifications
WARNING: Do not use this product in a manner not specified in this instruction manual.
Table 1 lists specifications for the H2S transmitter.
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 65-2422RK-05, you must follow the instructions and warnings
in this manual to assure proper and safe operation of the 65-2422RK-05 and to
minimize the risk of personal injury. Be sure to maintain and periodically
calibrate the 65-2422RK-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).
Input Voltage 11 VDC - 30 VDC
Sampling Method Diffusion
Signal Output 4 to 20 mA
Detection Range 0 to 100 PPM (parts per million)
Accuracy ± 5% of reading or ± 2 ppm H2S (whichever is greater)
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
Operating Temperature -40°F to 104°F (-40°C to 40°C)
!

6 • 65-2422RK-05 H2S Transmitter
Description
This section describes the components of the H2S transmitter. The transmitter consists of the
H2S detector, amplifier, and junction box.
Figure 1: H2S Transmitter Component Location
Test Point (+)
FB
TP+
4/20
OXY
+
24V
GW
Interconnect
Terminal Strip
Securing
Screw (2)
3/4 NPT Conduit Hub
SPAN
RD
ZERO
TP
OXY
TOXIC
Span
Potentiometer
Factory Set
Potentiometer
Zero
Potentiometer
Test Point (-)
BATT
TOXIC
+
BK
Jumper Block
InstalledToToxic
Select Header
Hydrogen
Sulfide
Amplifier
Detector
Terminal Strip
Hydrogen Sulfide
Detector

65-2422RK-05 H2S Transmitter • 7
H2S Detector
The H2S detector includes the detector housing body, detector housing cap, cap gasket, rubber
boot, spacer, and the plug-in H2S sensor.
Figure 2: H2S Detector Component Location
Detector Housing Body
The detector housing body protects the electronic components within the housing. Use the
mounting threads at the top of the housing to screw the H2S detector into the 3/4 NPT hub on
the bottom of the junction box. Two wires extend from the top of the detector housing body.
Use these wires to connect the H2S detector to the amplifier. One of the wires is red and one of
the wires is black.
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.
Housing Cap & Cap Gasket
The housing cap screws onto the detector housing. It retains the plug-in sensor and protects it
from damage. The housing cap also includes a flame arrestor which contains any sparks that
may occur within the detector and a flame arrestor guard which protects the flame arrestor
from damage. Unscrew the detector cap to access the plug-in sensor for maintenance or
replacement. A cap gasket seals the interface between the housing and cap.
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 • 65-2422RK-05 H2S Transmitter
Plug-In H2S Sensor
The sensor is secured within the sensor housing by the four pins. Through a series of chemical
and electrical reactions, the sensor produces an electrical output that is proportional to the
detector range of the transmitter.
Amplifier
The amplifier converts the electrical output from the sensor to a 4 to 20 mA signal (that is
proportional to the detection range) and transmits the signal to a gas monitoring controller.
The amplifier includes the amplifier type selector, detector terminal strip, interconnect
terminal strip, span pot, zero pot, and test points (see Figure 1).
Amplifier Type Selector
The amplifier type selector is near the bottom left corner of the amplifier. It is to the left of the
detector terminal strip and below the span potentiometer.
The amplifier included with the H2S transmitter is designed for use with RKI’s toxic gas and
oxygen transmitters. The amplifier type selector determines for which transmitter the
amplifier is intended. For H2S transmitters, a jumper block is installed over the TOXIC
selector (see Figure 1).
Detector Terminal Strip
The detector terminal strip is the four-point terminal strip near the bottom of the amplifier.
Use the detector terminal strip to connect the H2S detector to the amplifier.
NOTE: The H2S detector is factory-wired to the amplifier. See the Installation section of this
manual for all wiring procedures related to the transmitter.
Interconnect Terminal Strip
The interconnect terminal strip is the four-point terminal strip near the top of the amplifier.
Use the interconnect terminal strip to connect the amplifier to a controller.
Span Pot
The span pot is on the left side of the amplifier. Of the three potentiometers, the span pot is
bottom most. Use the span pot to adjust the transmitter’s response output during the
calibration procedure.
Zero Pot
The zero pot is above the span pot. Use the zero pot to adjust the transmitter’s target gas-free
output during the start-up and calibration procedures.
CAUTION:The third potentiometer is factory-set. Do not adjust it.

65-2422RK-05 H2S Transmitter • 9
Test Points
The test points (labeled TP- and TP+) are on the left and right side of the interconnect
terminal strip. The test points produce a 100 to 500 mV output that is proportional to the
transmitter’s 4 to 20 mA output. Use the test points and a voltmeter to measure the
transmitter’s output during the start-up and calibration procedures.
Junction Box
Use the junction box to install the H2S transmitter at a mounting site that is remote from the
controller. The junction box also protects the amplifier and wiring connections made to the
amplifier. Use the two 3/4 NPT conduit hubs to mount the detector to the junction box (bottom
hub) and connect wiring from the amplifier to the controller (top hub).
NOTE: The H2S detector and amplifier are factory-mounted to the junction box.
Use the junction box’s two mounting holes to mount the H2S transmitter to a vertical surface
at the monitoring site. Use the cover on the front of the junction box to access the interior of
the junction box.
Installation
This section describes procedures to mount the H2S transmitter in the monitoring environment
and wire the transmitter to a controller.
Mounting the H2S Transmitter
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 transmitter 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 transmitter at
approximately breathing level.

10 • 65-2422RK-05 H2S Transmitter
Figure 3: Mounting the H2S Transmitter
If the H2S detector is mounted to the junction box, skip to step 5. If not, continue with step 2.
NOTE: The H2S detector is normally provided with a Killark HKB junction box and an HFC
lid rated explosion proof for Class I, Groups B, C, and D. This combination is shown
in Figure 2 above. Any junction box with an internal volume less than or equal to 69
cubic inches and rated explosion proof for ClassI, Groups B, C, and D may be used.
2. Remove the junction box cover.
3. Guide the two wires that extend from the top of the H2S detector through the bottom
conduit hub of the junction box.
4. Screw the H2S detector into the bottom conduit hub of the junction box.
5. At the monitoring site, use #10 screws through the junction box’s two mounting holes to
secure the junction box to a vertical surface.
CAUTION:Mount the H2S transmitter with the detector facing down (see Figure 2).
Ø .25 Mouting Holes (2X)
5.46
8.7 max
5.2
2.75
6.1
1.1
3.4 max
3/4 NPT Conduit Hub
3.94

65-2422RK-05 H2S Transmitter • 11
Wiring the H2S Transmitter 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 incoming power at the controller.
3. Remove the junction box cover.
4. Verify that the detector leads are wired to the amplifier’s detector terminal strip.
If necessary, connect the detector leads to the detector terminal strip as shown in Figure 3.
5. Verify that the jumper block is installed over the TOXIC selector of the amplifier type
selector as shown in Figure 3.
6. Guide a two-conductor, shielded cable or two wires in conduit through the top conduit hub
of the junction box.
WARNING: To maintain the explosion proof classification of the H2S detector/junction box
combination, a conduit seal must be used within 18 inches of the junction box
conduit hub used for wiring to the controller.
7. Connect the two wires to the interconnect terminal strip as follows (see Figure 3).
• Connect the positive wire to the terminal labeled 24V +.
• Connect the feedback wire to the terminal labeled 4/20 FB.
CAUTION:If using shielded cable, leave the drain wire insulated and disconnected at the
transmitter. You will connect the opposite end of the cable’s drain wire at the
controller.
8. Secure the junction box cover to the junction box.
9. Route the cable or wires leading from the H2S transmitter through one of the conduit hubs
at the controller housing.
CAUTION:Do not route power and transmitter wiring through the same conduit hub. The
power cable may disrupt the transmission of the transmitter signal to the
controller.

12 • 65-2422RK-05 H2S Transmitter
10. Connect the wires to the to the applicable controller transmitter terminal strip as shown in
Figure 3.
Figure 4: Wiring the H2S Transmitter to a Controller
11. 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.
24V4/20
TOXIC
SPAN
BATT
FB
ZERO
H2S Detector,
Factory Wired
Jumper Block
Installed To Toxic
Select Header
Red
Black
Controller or Recording
Device
4-20mAIn(FB)
+ 24 VDC
Not Used
Factory Set Pot
Amplifier
GWRD BK
TP
+ +
TP +
TOXIC
OXY
OXY

65-2422RK-05 H2S Transmitter • 13
Start Up
This section describes procedures to start up the H2S transmitter and place the transmitter 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
instruction 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 instruction
manual.
CAUTION:Allow the transmitter to warm up for 5 minutes before you continue with the next
section, “Setting the Zero Signal”.
Setting the Zero Signal
WARNING: 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.
NOTE: If you can verify that the detector is in a fresh air environment (environment known to
be of normal oxygen content and free of toxic and combustible gases), it is not
necessary to apply zero air when verifying or setting the fresh air reading.
The procedure below describes applying zero emission air, usually called zero air, 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.
1. Unscrew and remove the junction box cover from the junction box.
2. Set a voltmeter to measure in the millivolt (mV) range.
3. Plug the voltmeter leads into the test points on the amplifier. Plug the positive lead into the
test point labeled TP+; plug the negative lead into the test point labeled TP-.
4. Screw the calibration cup onto the bottom of the detector.
5. Screw the regulator into the zero air calibration cylinder.
6. Use the sample tubing to connect the regulator to the calibration cup.
7. Turn the regulator’s on/off knob counterclockwise to open it. Gas will begin to flow.
8. Allow the gas to flow for 2 minutes.
9. Verify a voltmeter reading of 100 mV (±2 mV).

14 • 65-2422RK-05 H2S Transmitter
10. If necessary, use a flat-blade screwdriver to adjust the span pot until the voltmeter reading
is 100 mV (±2 mV).
11. Turn the regulator’s on/off knob clockwise to close it.
12. Unscrew the calibration cup from the detector.
13. Unscrew the regulator from the zero air calibration cylinder. For convenience, leave the
sample tubing connected to the regulator and the calibration cup.
14. Store the components of the calibration kit in a safe and convenient place.
15. Remove the voltmeter leads from the test points.
16. Secure the junction box cover to the junction box.
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 transmitter. 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 transmitter 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 transmitter.
NOTE: This troubleshooting guide describes transmitter problems only. See the controller
instruction manual for problems you may encounter with the controller.
Fail Condition
Symptoms
• The controller indicates a fail condition.
Probable causes
• The transmitter wiring is disconnected or misconnected.
• The transmitter’s zero reading is low enough to cause a fail condition.
• The transmitter is malfunctioning.

65-2422RK-05 H2S Transmitter • 15
Recommended action
• Verify that the transmitter wiring is correct and secure.
• Calibrate the transmitter.
• If the fail condition continues, replace the H2S sensor.
• 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 transmitter requires frequent calibration.
NOTE: Under “normal” circumstances, the transmitter 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 transmitter 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 Transmitter
This section includes procedure to replace the H2S sensor and amplifier. A procedure to
replace the entire detector assembly is at the end of this section. 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 incoming power at the controller.
3. Unscrew the bottom section of the H2S detector housing from the top section.
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.

16 • 65-2422RK-05 H2S Transmitter
6. Install the spacer and rubber boot onto the replacement sensor’s face.
7. Carefully plug the replacement sensor into the socket pattern that is located in the top
section of the detector housing.
NOTE: Match the sensor’s male pins with the four female sockets as you plug the sensor into
the socket.
8. Screw the bottom section of the detector housing onto the top section.
9. Turn on or plug in incoming power at the power source end.
10. Turn on the controller.
CAUTION:Allow the replacement sensor to warm up for 5 minutes before you continue with
the next step.
11. Calibrate the replacement sensor as described in the Calibration section of this manual.
Replacing the Amplifier
1. Turn off the controller.
2. Turn off or unplug incoming power at the power source end.
3. Remove the junction box cover.
4. Disconnect the detector leads from the detector terminal strip.
5. Unscrew and remove the two screws that secure the amplifier to the junction box.
The screws are at the top left and bottom right of the amplifier.
6. Remove the amplifier.
7. Place the new amplifier in the same position as the old amplifier.
8. Use the two screws you removed in step 5 to secure the new amplifier to the junction box.
9. Verify that the jumper block is installed over the TOXIC selector of the amplifier type
selector as shown in Figure 3.
10. Reconnect the wiring from the controller to the interconnect terminal strip as shown in
Table 2 and Figure 3.
Table 2: Reconnecting the H2S Amplifier to a Controller
Amplifier Interconnect
Terminal Strip
Controller Transmitter
Terminal Strip (typical)
4/20 FB 4 -20 (FB)
24V + + V (11 - 30 VDC)

65-2422RK-05 H2S Transmitter • 17
11. Reconnect the detector leads to the detector terminal strip as shown in Table 3 and Figure
3.
12. Reinstall the junction box cover.
13. Turn on or plug in incoming power at the power source end.
14. Turn on the controller.
CAUTION: Allow the sensor to warm up for 5 minutes before you continue with the next step.
15. Calibrate the H2S transmitter 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 incoming power at the power source end.
3. Remove the junction box cover.
4. Disconnect the detector leads from the detector terminal strip. Note the position of the
color-coded leads as you remove them.
5. Unscrew the detector from the junction box.
6. Guide the detector leads of the replacement detector through the bottom conduit hub of the
junction box, then screw the mounting threads of the detector into the conduit hub.
7. Connect the detector leads to the detector terminal strip as shown in Table 4 and Figure 3.
8. Reinstall the junction box cover.
9. Turn on or plug in incoming power at the controller.
Table 3: Reconnecting the H2S Detector to the Amplifier
H2S Detector Lead Amplifier Interconnect
Terminal Strip
Black TOXIC BK
Red TOXIC RD
Table 4: Connecting the Replacement H2S Detector to the Amplifier
H2S Detector Lead Amplifier Interconnect
Terminal Strip
Black TOXIC BK
Red TOXIC RD

18 • 65-2422RK-05 H2S Transmitter
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 the Calibration section of this manual.
12. Secure the junction box cover to the junction box.
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 transmitter. It includes procedures to prepare
for calibration, set the zero reading, set the response reading, and return to normal operation.
It describes the test 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 transmitter may cause alarms. Be sure to put the controller into its
calibration program or disable external alarms before 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 fixed flow regulator to the calibration cup.
4. Set a voltmeter to measure in the millivolt (mV) range.
WARNING: 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.

65-2422RK-05 H2S Transmitter • 19
5. Remove the junction box cover, then plug the voltmeter leads into the test points on the
amplifier.
Plug the positive lead into the test point labeled TP+; plug the negative lead into the test
point labeled TP-.
6. Use the following formula to determine the correct test points output for the calibrating
sample.
Output (mV) = (calibrating sample/fullscale) X 400 + 100
For example, with a calibrating sample of 25 PPM H2S and a fullscale setting of 100 PPM,
the correct output is 200 mV.
200 (mV) = (25/100) X 400 +100
Setting the Zero Reading
NOTE: If you can verify that the H2S transmitter is in a fresh air environment, you do not
need to apply zero air to the detector before adjusting the zero reading.
1. Turn the regulator on/off knob counterclockwise to open it. Gas will automatically begin
to flow.
2. Allow the gas to flow for two minutes.
3. Verify a reading of 100 mV (± 2mV).
4. If necessary, use the zero pot on the amplifier to adjust the reading to 100 mV (± 2mV).
5. 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. Verify that the calibration gas is representative of the transmitter’s target gas.
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. Open the regulator by turning the knob
counterclockwise and then install it onto the cylinder.
3. Allow the gas to flow for two minutes.
4. Verify that the reading matches the response reading (± 2mV) you determined earlier.
5. If necessary, use the span pot on the amplifier to adjust the reading to match the correct
response reading.
6. Turn the regulator on/off knob clockwise to close it.
7. Unscrew the regulator from the calibration cylinder.
8. Unscrew the calibration cup from the detector.

20 • 65-2422RK-05 H2S Transmitter
NOTE: For convenience, leave the components of the calibration kit connected by the sample
tubing.
Returning to Normal Operation
1. Remove the voltmeter leads from the amplifier test points.
2. Secure the junction box cover to the junction box.
3. When the display reading falls below the alarm setpoints, return the controller to normal
operation.
4. Verify that the controller display reading decreases and stabilizes at 0 ppm.
5. 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 transmitter.
Table 5: 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
18-0405RK-01 Junction box (without cover; pre drilled for amplifier)
18-0406RK Junction box cover
57-1060RK Amplifier (specify target gas when ordering)
65-2422RK-05 H2S transmitter (includes detector and amplifier), CSA classified
65-2428 H2S replacement detector assembly (includes sensor), CSA classified
71-0113RK 65-2422RK-05 H2S Transmitter Operator’s Manual (this document)
81-0076RK-01 Zero air calibration cylinder, 34 liter steel
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 calibration cyl-
inders (cylinders with external thread)
81-1051RK Regulator with gauge and knob, 0.5 LPM, for 34 liter aluminum calibration cylinders
and 58 liter and 103 liter steel calibration cylinders (cylinders with internal thread)
81-1117RK Calibration cup
ES-1537-H2S H2S replacement sensor