RKI Instruments 65-2424RK User manual

www.rkiinstruments.com
65-2424RK
Hydrogen Sulfide Transmitter
Operator’s Manual
Part Number: 71-0062RK
Revision: B
Released: 6/12/20

2 • 65-2424RK 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.

65-2424RK H2S Transmitter • 3
Product Warranty
RKI Instruments, Inc. warranties 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 • 65-2424RK H2S Transmitter
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
H2S Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Sealing Spacer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Amplifier PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Enclosure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Mounting the H2S Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Wiring the H2S Transmitter to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Preventive Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Replacing Components of the H2S Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Setting the Response Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

65-2424RK H2S Transmitter • 5
Overview
This manual describes the 65-2424RK 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
Table 1 lists specifications for the H2S transmitter.
WARNING: When using the 65-2424RK, you must follow the instructions and warnings in
this manual to assure proper and safe operation of the 65-2424RK and to
minimize the risk of personal injury. Be sure to maintain and periodically
calibrate the 65-2424RK as described in this manual.
Table 1: Specifications
Target Gas Hydrogen sulfide (H2S)
Sampling Method Diffusion
Input Voltage 10 VDC - 30 VDC
Signal Output 4 - 20 mA
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

6 • 65-2424RK H2S Transmitter
Description
This section describes the components of the H2S transmitter. The transmitter consists of the
H2S sensor, sealing spacer, amplifier printed circuit board (PCB), and enclosure.
Figure 1: H2S Transmitter Component Location
H2S Sensor
The sensor is cylindrical with the sensing face on the top and the connection pins on the
bottom. The sensor plugs into the amplifier PCB with the four pins. The sensor is exposed to
the ambient air through an opening in the enclosure cover. Through a series of chemical and
electrical reactions, the sensor produces an electrical output that is proportional to the
detection range of the transmitter.
Sealing Spacer
The ring shaped plastic sealing spacer fills a gap in the rubber boot that is installed on the
sensor. The rubber boot is used to seal the sensor to the enclosure cover in both the CO and
H2S transmitters. In the CO transmitter the rubber boot also retains a charcoal filter. Since a
charcoal filter is not used in the H2S transmitter, the sealing spacer fills the space that would
be filled by the charcoal filter’s body.
ZERO
R
CAL-
CAL+
+V
FB
B
SPAN
Sensor (w/sealing
spacer & boot)
Enclosure
(shown w/out cover)
Interconnect
Terminal Strip
Amplifier PCB
Zero Pot
Span Pot
Test Point CAL-
Factory Set Pot
Amplifier PCB Mounting
Screw (under sensor)
Cable Bushing
Amplifier PCB
Mounting Screw
Test Point
CAL+

65-2424RK H2S Transmitter • 7
Amplifier PCB
The amplifier PCB 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 PCB includes the interconnect terminal strip, sensor sockets, span pot, zero pot,
and test points (see Figure 1).
Interconnect Terminal Strip
The interconnect terminal strip is the four-point terminal strip on the lower left side of the
amplifier PCB. Use the interconnect terminal strip to connect the transmitter to a controller.
Sensor Sockets
There are four sensor sockets located in a circular pattern near the top of the amplifier PCB.
The sensor plugs into these sockets.
Span Pot
The span pot is near the bottom right corner of the amplifier PCB. 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:There is a third potentiometer on the PCB, the null potentiometer. It is factory-set.
Do not adjust it.
Test Points
The test points (labeled CAL+ and CAL-) are on the right of the interconnect terminal strip.
The test points produce a 100 - 500 mV output that is proportional to the transmitter’s 4 - 20
mA output. Use the test points and a voltmeter to measure the transmitter’s output during the
start-up and calibration procedures.
Enclosure
The enclosure enables you to install the H2S transmitter at a mounting site that is remote from
the controller. The enclosure also protects the amplifier PCB and wiring connections made to
the transmitter. Use the cable bushing on the bottom of the enclosure to connect wiring from
the amplifier PCB to a controller.
Use the enclosure’s two mounting holes, accessible with the cover removed, to mount the H2S
transmitter to a vertical surface at the monitoring site. Use the cover on the front of the
enclosure to access the interior of the enclosure.

8 • 65-2424RK H2S Transmitter
Installation
This section describes procedures to mount the H2S transmitter in the monitoring environment
and wire the transmitter to a gas monitoring 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.
Figure 2: Mounting the H2S Transmitter
2. Remove the enclosure’s cover by unscrewing the four cover screws, one at each corner.
3. At the monitoring site, use #6 screws through the enclosure’s two mounting holes to
secure it to a vertical surface.
4. Secure the cover to the enclosure with the four cover screws.
1.50 .54
.24
2.52
H S Sensor
2
3.86 3.39
1.42
Ø .160 mounting hole,
2X, Accessible With Lid
Removed
.80 max Cable Bushing

65-2424RK H2S Transmitter • 9
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 power source end.
3. Remove the enclosure’s cover by unscrewing the four cover screws, one at each corner.
4. Guide a two-conductor, shielded cable through the cable bushing at the bottom of the
enclosure.
5. Connect the two wires to the interconnect terminal strip as follows (see Figure 3).
• Connect the positive wire to the terminal labeled +V.
• Connect the feedback wire to the terminal labeled FB.
CAUTION:Leave the shield drain wire insulated and disconnected at the transmitter. You will
connect the opposite end of the cable’s drain wire at the controller.
6. Secure the cover to the enclosure.
7. Route the cable leading from the H2S transmitter through one of the conduit hubs at the
controller housing.
CAUTION:Do not route controller power and transmitter wiring through the same conduit
hub. The power cable may disrupt the transmission of the transmitter signal to the
controller.

10 • 65-2424RK H2S Transmitter
8. Connect the wires to the applicable controller transmitter terminal strip as shown in Figure
3 below.
Figure 3: Wiring the H2S Transmitter to a Controller
9. 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.
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
operator’s manual.
3. Turn on or plug in the incoming power to the controller, then turn on the controller.
4. Verify that the controller is on and operating properly. Refer to the controller operator’s
manual.
Controller or Recording
Device
4-20mAIn(FB)
+ (10 VDC - 30VDC)
ZERO
SPAN
CAL+
CAL-
+V
R
FB
B