RKI Instruments 65-2397RK User manual

RKI Instruments, Inc.
www.rkiinstruments.com
65-2397RK
CO2 Transmitter
Operator’s Manual
Part Number: 71-0185RK
Revision: C
Released: 9/1/20

2 • 65-2397RK CO2 Transmitter
WARNING
Read and understand this instruction manual before operating
transmitter. Improper use of the transmitter could result in bodily
harm or death.
Periodic calibration and maintenance of the transmitter is essential for
proper operation and correct readings. Please calibrate and maintain
this transmitter regularly! Frequency of calibration depends upon the
type of use you have and the sensor types. Typical calibration
frequencies for most applications are between 6 and 12 months, but
can be required more often or less often based on your usage.

65-2397RK CO2 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 A PARTICULAR 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 • 65-2397RK CO2 Transmitter
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
CO2 Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Mounting the CO2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Wiring the CO2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Setting the Zero Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Replacing Components of the CO2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Setting the Response Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

65-2397RK CO2 Transmitter • 5
Overview
This manual describes the 65-2397RK CO2 transmitter. This manual also describes how to install, start
up, configure, maintain, and calibrate the transmitter 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 CO2 transmitter.
Specifications
Table 1 lists specifications for the CO2 transmitter.
WARNING: When using the 65-2397RK, you must follow the instructions and warnings in this
manual to assure proper and safe operation of the 65-2397RK and to minimize the
risk of personal injury. Be sure to maintain and periodically calibrate the 65-2397RK
as described in this manual.
Table 1:Specifications
Targ et Gas Carbon Dioxide (CO2)
Sampling Method Diffusion
Signal Output 4 to 20 mA
Detection Range 65-2397RK-01: 0-9,000 ppm
65-2397RK-02: 0-5,000 ppm
65-2397RK-03: 0-5% Volume
65-2397RK-04: 0-20% Volume
65-2397RK-05: 0-50% Volume
65-2397RK-10: 0-100% Volume
Response Time 90% in 45 seconds
Operating Temperature -4°F to 122°F (-20°C to 50°C)
Accuracy ± 5% of reading or ± 2% of full scale (whichever is greater)

6 • 65-2397RK CO2 Transmitter
Description
This section describes the components of the CO2 transmitter. The transmitter is a 4 - 20 mA type
detector head. It consists of the CO2 detector, amplifier, and junction box.
Figure 1: CO2 Transmitter Component Location
G
LEL BWR
Amplifier
Controller Terminal Strip
S
PWR/SIG
J-Box
IR CO2 Detector
Detector Terminal
Strip
Sensor
Current
mA SPAN
Jumper Pins,
Factory Use Only
Factory Adjust Pot
Zero Pot
Span Pot
Factory Adjust Pot
ZERO
- Test Point
+ Test Point

65-2397RK CO2 Transmitter • 7
Infrared CO2 Detector
The CO2 detector consists of the detector housing body, detector housing cap, cap gasket, and the plug-
in sensor.
Figure 2: CO2 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 CO2 detector into the 3/4 NPT hub on the bottom of the
junction box. Four color coded leads, red, white, green, and black, extend from the other end of the
detector. The leads allow you to connect the detector to the amplifier.
The housing includes three sockets installed on a circuit board. These sockets accept the plug-in
sensor’s three pins to provide an electrical connection for the sensor. The circuit board with the sockets
conditions the sensor’s signal before the signal reaches the amplifier.
Housing Cap & Cap Gasket
The housing cap screws onto the detector housing. It retains the plug-in sensor and protects it from
damage. A foam gasket is installed inside the housing cap that seals against the sensor face. A
hydrophobic membrane on the outside of the cap face keeps water and particulates away from the
sensor face behind the cap. 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.
Plug-In CO2Sensor
The plug-in sensor is secured in the detector assembly by the housing cap. The sensor produces a
millivolt output that corresponds to the detection range of the transmitter.
Hydrophobic
Membrane
Cap Gasket
Plug-In CO2 Sensor
Sensor Retainer
Detector Housing Cap
Detector Housing Body

8 • 65-2397RK CO2 Transmitter
Amplifier
The amplifier converts the electrical output from the detector to a 4 to 20 mA signal that corresponds
to the detection range and transmits the signal to a gas monitoring controller. A foam gasket that
orients the amplifier and keeps it from rotating is installed on the bottom of the amplifier. The
amplifier includes the controller terminal strip, detector terminal strip, span pot, zero pot, and test
points (see Figure 1).
Controller Terminal Strip
The controller terminal strip is a three position plug-in style terminal strip located near the top of the
amplifier. Use the controller terminal strip to wire the CO2 transmitter to a controller.
Detector Terminal Strip
The detector terminal strip is a four position plug-in style terminal strip located below the controller
terminal strip. Use the detector terminal strip to connect the CO2 transmitter to the amplifier.
NOTE: The IR CO2 detector is factory-wired to the detector terminal strip. See “Wiring the CO2
Transmitter to a Controller” on page 10 for all wiring procedures related to the transmitter.
Zero Pot
The zero pot is located in the upper left corner of the amplifier (see Figure 1). Use a small flat blade
screwdriver to turn the zero pot’s adjustment screw and adjust the amplifier’s target gas-free output
during the start-up and calibration procedures. Turn the adjustment screw clockwise to increase the
zero output and counterclockwise to decrease the zero output.
Span Pot
The span pot is located to the right of the zero pot (see Figure 1). Use a small flat blade screwdriver to
turn the span pot’s adjustment screw and adjust the amplifier’s gas response output during the
calibration procedure. Turn the adjustment screw clockwise to increase the gas response and
counterclockwise to decrease the gas response.
CAUTION: The amplifier includes two additional potentiometers. They are factory-set. Do not adjust
them.
Test Points
The test points are on the left side of the amplifier (see Figure 1). The test points produce a 100 mV to
500 mV output that corresponds to the transmitter’s 4 to 20 mA output. Use the test points and a
voltmeter to measure the amplifier’s output during the start-up and calibration procedures. The black
test point in the lower left corner is the negative (-) test point and the red test point below the zero pot
is the positive (+) test point.
Junction Box
Use the junction box to install the transmitter at a mounting site that is remote from the controller. The
junction box protects the amplifier and wiring connections made to the amplifier. Use the top 3/4 NPT
conduit hub to connect wiring from the amplifier to the controller. Use the cover on the front of the
junction box to access the interior of the junction box. The detector and amplifier are factory installed
in the junction box. 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

65-2397RK CO2 Transmitter • 9
on the detector during calibration.
Installation
This section describes procedures to mount the CO2 transmitter in the monitoring environment and
wire the transmitter to a controller.
Mounting the CO2 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.
• Mount the transmitter at least six feet from the floor to minimize the possibility of someone
breathing on the unit. The exhaled CO2 may cause an alarm.
Figure 3: Mounting the CO2 Transmitter
.38
.75
3.10
Rubber
Spacers,
3X
3/4 NPT
Female
3.65
IR CO2
Detector
J-Box
1 1/2-20 Thread for
Calibration Cup
6.80 MAX

10 • 65-2397RK CO2 Transmitter
2. At the monitoring site you select, hang or mount the junction box with the detector facing down
(see Figure 3).
Wiring the CO2 Transmitter to a Controller
WARNING: Always verify that the power to the controller 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.
4. The detector leads are factory wired. Verify that the detector leads are wired to the amplifier’s
detector terminal strip as shown in Figure 4.
5. To gain access to a plug-in terminal strip for wiring, pull it out of its socket by grasping the
terminal strip and pulling. The detector strip is keyed so that the controller and detector terminal
strips cannot be reversed inadvertently.
6. Guide a three-conductor, shielded cable, or three wires in conduit through the top conduit hub of
the junction box.
7. Pull out the controller terminal strip, and connect the three wires to the terminal strip as follows
(see Figure 4).
• Connect the positive wire to the PWR/SIG “+” terminal.
• Connect the signal wire to the PWR/SIG “S” terminal.
• Connect the negative wire to the PWR/SIG “-” terminal.
CAUTION: If shielded cable is used, leave the cable shield’s drain wire disconnected and insulated at
the transmitter. You will connect the opposite end of the cable’s drain wire to the
controller’s chassis (earth) ground.
8. Reinstall the controller terminal strip into its socket.
9. Secure the junction box cover to the junction box.
10. Route the cable or wires leading from the CO2 transmitter 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, are not
explosion-proof, and must be installed in a non-hazardous location.