RKI Instruments CT-7 Series User manual

www.rkiinstruments.com
65-2302/65-2303
CT-7 Series
Toxic Detector
Operator’s Manual
Part Number: 71-0422
Revision: H
Released: 6/24/21

2 • 65-2302/65-2303 Toxic Detector
WARNING
Read and understand this instruction manual before operating
detector. 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
frequencies for most applications are between 3 and 6 months, but can
be required more often or less often based on your usage.

65-2302/65-2303 Toxic 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 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 • 65-2302/65-2303 Toxic Detector
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
65-2302 Toxic Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Junction Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Mounting the Toxic Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Wiring the Toxic Detector to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Setting the Zero (Fresh Air) Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Replacing Components of the Toxic Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Special Note About Calibrating a ClO2Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Setting the Zero (Fresh Air) Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Setting the Response Reading (Span) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Returning to Normal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

65-2302/65-2303 Toxic Detector • 5
Overview
This manual describes the 65-2302 and 65-2303 toxic detectors. This manual also describes
how to install, start up, maintain, and calibrate the toxic detector when used with a gas
monitoring controller. A parts list at the end of this manual lists replacement parts and
accessories for the toxic detector.
The 65-2303 toxic detector includes the 65-2302 toxic detector and a junction box.
The 65-2302 toxic detector does not include a junction box and is normally mounted in one of
a controller’s conduit hubs. If you are using a 65-2302 toxic detector, disregard all references
to the junction box and junction box terminal strip.
The 65-2302 and 65-2303 detectors can be used for various target gases which are listed in
Table 1 below.
Specifications
WARNING: Do not use this product in a manner not specified in this instruction manual.
Table 1: Specifications
Target Gas and
Detection Range
Ammonia (NH3) 0 - 75 ppm • 65-2302-NH3-75
• 65-2303-NH3-75
Ammonia (NH3) 0 - 100 ppm • 65-2302-NH3-1
• 65-2303-NH3-1
Ammonia (NH3) 0 - 200 ppm • 65-2302-NH3-2
• 65-2303-NH3-2
Ammonia (NH3) 0 - 500 ppm • 65-2302-NH3-5
• 65-2303-NH3-5
Chlorine (Cl2) 0 - 3.00 ppm • 65-2302-CL2-3
• 65-2303-CL2-3
Chlorine (Cl2) 0 - 5.00 ppm • 65-2302-CL2-5
• 65-2303-CL2-5
Chlorine (Cl2) 0 - 10.0 ppm • 65-2302-CL2-10
• 65-2303-CL2-10
Chlorine Dioxide (ClO2) 0 - 1.00 ppm • 65-2302-CLO2-1
• 65-2303-CLO2-1
Chlorine Dioxide (ClO2) 0 - 3.00 ppm • 65-2302-CLO2-3
• 65-2303-CLO2-3
Chlorine Dioxide (ClO2) 0 - 5.00 ppm • 65-2302-CLO2-5
• 65-2303-CLO2-5
Hydrogen Cyanide (HCN) 0 - 15 ppm • 65-2302-HCN-15
• 65-2303-HCN-15

6 • 65-2302/65-2303 Toxic Detector
WARNING: When using the 65-2302/65-2303, you must follow the instructions and
warnings in this manual to assure proper and safe operation of the 65-2302/
65-2303 and to minimize the risk of personal injury. Be sure to maintain and
periodically calibrate the 65-2302/65-2303 as described in this manual.
Description
This section describes the components of the 65-2302 and 65-2303. The 65-2303 includes the
65-2302 toxic detector and a junction box. The 65-2302 does not include a junction box.
Figure 1 below shows the components of the 65-2303.
Sampling Method Diffusion
Accuracy ± 10% of reading or ± 5% of full scale (whichever is greater)
Response Time T90 in 60 seconds
Operating Temperature &
Humidity
-4°F to 104°F (-20°C to 40°C)
Table 1: Specifications
3/4 NPT Conduit Hub
Junction Box
Detector
Figure 1: 65-2303 Component Location

65-2302/65-2303 Toxic Detector • 7
65-2302 Toxic Detector
The 65-2302 toxic detector consists of the detector housing body, detector housing cap, cap
gasket, and the plug-in sensor.
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 detector into a 3/4 NPT hub. Two
wires extend from the top of the detector housing body. Use these wires to connect the
detector to a controller. One of the wires is black and one of the wires is color-coded
depending on the detector type. See Figure 4 on page 10 for the color code assignments.
The housing body includes a four-socket pattern at the bottom of the housing body. The plug-
in sensor mates to this socket pattern. A pre-amplifier located between the sockets and the two
wires conditions the sensor’s signal before the signal reaches the controller. Each plug-in
sensor type (Cl2for example) requires a different pre-amplifier, so there is a different detector
housing body for each gas type.
Housing Cap and Cap Gasket
The housing cap screws onto the detector housing. It retains the sensor and protects it from
damage. A foam gasket inside the housing cap seals against the face of the sensor when the
cap is screwed on the housing body. Unscrew the detector cap to access the sensor for
replacement. A cap gasket seals the interface between the housing and cap.
Plug-in Sensor
The plug-in sensor is secured in the detector assembly by the housing cap. There is a different
sensor for each target gas. Through a series of chemical and electrical reactions, the sensor
produces an electrical output that corresponds to the detection range of the sensor. A
VersaporR membrane is installed on the sensor face for protection from water and debris.
Junction Box
The junction box protects the detector wiring connections and allows you to install the toxic
detector at a mounting site that is remote from a controller. Two conduit hubs allow you to
mount the toxic detector to the junction box and connect the wiring from the detector to a
Plug-in Sensor
(different for each detector type)
Detector
Housing Cap
VersaporR Membrane
Detector Housing Body
(different for each detector type)
Cap Gasket
Figure 2: 65-2302 Toxic Detector Component Location

8 • 65-2302/65-2303 Toxic Detector
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. A terminal block within the junction box
facilitates the wiring connections. 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 toxic detector in the monitoring environment
and wire the detector to a controller.
Mounting the Toxic Detector
NOTE: If you are installing a 65-2302, it does not include a junction box and is usually
factory installed in one of a controller’s conduit hubs or may be field installed using
the 3/4 NPT threads on the end with the wires. The 65-2303 includes a junction box
as shown in Figure 3 below.
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.

65-2302/65-2303 Toxic Detector • 9
NOTE: If your application does not require a specific mounting site, mount the detector at
approximately breathing level.
2. At the mounting site you select, hang or mount the junction box with the detector facing
down (see Figure 3).
CAUTION:Mount the toxic detector with the detector facing down (see Figure 3.)
Wiring the Toxic Detector to a Controller
WARNING: Always verify that 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. If the detector is mounted remotely from a controller using the junction box, proceed to
step 4.
If the detector is mounted directly to a controller, connect the detector’s color-coded and
black wires to the appropriate controller detector terminals (see Figure 4 for the color
coding of the non-black wire) and skip to the Startup Section.
4. Remove the junction box cover.
Figure 3: Outline and Mounting Dimensions
Rubber
Spacer, 3X
.38
.75
3.10
Detector
+3/4" NPT
7.30 .25
3.65
65-2302
1 1/2-20 Thread for
Calibration Cup
Ø1.75
3/4 NPT
Conduit Hub
1 1/2-20 Thread for
Calibration Cup
Junction
Box
65-2303
6.70 Max
.75
1.22

10 • 65-2302/65-2303 Toxic Detector
5. Guide a two-conductor, shielded cable or two wires in conduit through the unused conduit
hub of the junction box. Use appropriate conduit fittings and construction technique for
the environmental rating of the junction box. The junction box is rated NEMA 4X.
6. Connect the two wires to the detector using the 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 toxic 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.
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 65-2302 or 65-2303
detector.
10. 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.
(+) See Table
CL2
CLO2
HCN violet
yellow
Controller Detector Terminals,
Typical Designations
Controller Housing
+
S
Terminal Strip
Detector
Black (S)
Shielded
Cable
Gas Type + Wire
white
redNH3
Figure 4: Wiring to a Controller

65-2302/65-2303 Toxic Detector • 11
11. Reinstall the junction box cover.
Start Up
This section describes procedures to start up the toxic 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, then turn on the controller.
4. Verify that the controller is on and operating properly. Refer to the controller operator’s
manual.
CAUTION:For all gases except ClO2: Allow the detector to warm up for 15 minutes before
you continue with the next section, “Setting the Zero Reading”.
For ClO2: Allow the detector to warm up for 2-3 hours before you continue with
the next section, “Setting the Zero Reading”.
Setting the Zero (Fresh Air) Reading
CAUTION: If you suspect the presence of the target gas in the monitoring environment, use
the calibration kit and a zero air calibration cylinder to introduce “fresh air” to
the toxic detector and verify an accurate zero setting.
CAUTION:For all gases except ClO2: Allow the detector to warm up for 15 minutes before
setting the zero reading.
For ClO2: Allow the detector to warm up for 2-3 hours before setting the zero
reading.
1. Verify a reading of 0 ppm at the controller.
If the display reading is 0 ppm, start up is complete. The toxic detector is in normal
operation.
If the display reading is not 0 ppm, continue with step 2 or step 3, depending on the type of
environment the detector is installed in.
2. For a fresh air environment (an environment known to be free of toxic and combustible
gases, and of normal oxygen content, 20.9%), set the zero reading according to the
controller operator’s manual.

12 • 65-2302/65-2303 Toxic Detector
3. For a non-fresh air environment:
a. Screw the calibration cup onto the bottom of the detector.
b. Screw the regulator into the zero air calibration cylinder.
c. Use the sample tubing to connect the regulator to the calibration cup.
d. Follow the instructions in the controller operator’s manual for setting the zero
reading.
e. 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.
f. Allow the gas to flow for two minutes.
g. Set the fresh air reading according to the controller operator’s manual.
h. Turn the regulator’s on/off knob clockwise to close it.
i. Unscrew the regulator from the calibration cylinder.
j. Unscrew the calibration cup from the detector. For convenience, leave the sample
tubing connected to the calibration cup and the regulator.
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 toxic detector. It includes daily and quarterly procedures.
Daily
Verify a display reading of 0 ppm at the controller. Investigate significant changes in the
display reading.
Quarterly
Calibrate the toxic detector as described in “Calibration” on page 18.

65-2302/65-2303 Toxic Detector • 13
Troubleshooting
The troubleshooting guide describes symptoms, probable causes, and recommended action for
problems you may encounter with the toxic 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 plug-in sensor is not properly plugged into the socket in the detector housing body.
NOTE: It could take up to 40 minutes for a disconnected NH3plug-in sensor to trigger a fail
condition.
• 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.
• Confirm that the plug-in sensor is installed properly.
• Perform a zero (fresh air) adjustment. A full calibration is recommended.
• If the fail condition continues, replace the plug-in 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.
NOTE: Under “normal” circumstances, the detector requires calibration once every three
months. Some applications may require a more frequent calibration schedule. See
“Calibration Frequency” on page 17 for a discussion of the calibration frequency.
Probable causes
• The plug-in sensor has been replaced and the shorting jumper has not been removed.
• The calibration cylinder is low, out-dated, or defective.
• The incorrect calibration cup or regulator is being used.

14 • 65-2302/65-2303 Toxic Detector
• The VersaporR membrane on the plug-in sensor face is blocked with dirt or some other
particulate contamination.
• The detector is malfunctioning.
Recommended action
1. Confirm that the shorting jumper on the plug-in sensor pins has been removed.
2. Verify that the calibration cylinder contains an adequate supply of gas.
3. Confirm that you are using the correct calibration cup and regulator. See “Parts List” on
page 20 for the required calibration cup and regulator.
4. Check the plug-in sensor face and remove any particulate contamination from the
VersaporR membrane if necessary. If the membrane appears saturated with contamination
or damaged, replace the membrane as described in “Replacing the VersaporR Membrane”
on page 15.
5. If the calibration/response difficulties continue, replace the plug-in sensor as described
later in this section.
6. If the calibration/response difficulties continue, contact RKI Instruments, Inc. for further
instruction.
Replacing Components of the Toxic Detector
This section includes a procedure to replace the plug-in toxic sensor, the VersaporR
membrane, and the entire toxic detector assembly. In most cases, it is not necessary to replace
the entire detector assembly.
Replacing the Plug-in Toxic Sensor
CAUTION:The plug-in 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 toxic sensor.
5. 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.

65-2302/65-2303 Toxic Detector • 15
WARNING: The toxic sensor will not operate properly if the wire jumper is not removed.
6. Carefully plug the replacement sensor into the four-socket pattern located in the detector
housing body.
WARNING: You must replace the plug-in sensor with the same type of sensor that is
installed. A detector cannot be converted from one type of detector to another
by using a different plug-in sensor. For example, if you are replacing a Cl2
sensor, you must replace it with a Cl2sensor.
7. Make sure the cap gasket is in place and screw the detector housing cap back onto the
detector housing body.
8. Turn on power to the controller.
9. Turn on the controller.
CAUTION:For all gases except ClO2: Allow the replacement sensor to warm up for 15
minutes before you continue with the next step.
For ClO2: Allow the replacement sensor to warm up for 2-3 hours before you
continue with the next step.
10. Calibrate the detector as described in “Calibration” on page 18.
Replacing the VersaporR Membrane
1. Turn off the controller.
2. Turn off or unplug incoming power to the controller.
3. Unscrew the detector housing cap from the detector housing body.
4. Unplug the plug-in sensor from the four-socket pattern in the detector housing body.
5. Gently pry up the edge of the white VersaporR membrane from the sensor face with a
small flat blade screwdriver or a similar tool.
6. Peel off the VersaporR membrane. It may be necessary to clean off the sensor face to
remove any residue left from the adhesive backed membrane.
7. Install the new membrane on the face of the plug-in sensor.
Figure 5: Plug-In Sensor Jumper Removal
Remove jumper

16 • 65-2302/65-2303 Toxic Detector
8. Plug the sensor back into the four-socket pattern in the detector housing body.
9. Make sure the cap gasket is in place and screw the detector housing cap back onto the
detector housing body.
10. Turn on power to the controller.
11. Turn on the controller.
Replacing the Toxic Detector
NOTE: In most cases, it is only necessary to replace the plug-in 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 conduit hub.
6. Guide the detector leads of the replacement detector through the controller conduit hub or
junction box conduit hub, then screw the mounting threads of the detector into the hub. If
necessary for environmental conditions, apply thread sealant or Teflon tape to the hub and/
or detector threads to seal them.
7. If the detector is installed directly on a controller, connect the detector leads to the
appropriate detector terminal strip terminals. See Figure 4 on page 10 for wiring to a
generic controller. See the controller operator’s manual and the controller’s detector head
specification sheet for the 65-2302 or 65-2303 detector for wiring specific to your
controller.
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
Figure 4 on page 10). See the controller operator’s manual and the controller’s detector
head specification sheet for the 65-2302 or 65-2303 to verify the connections to the
controller 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.

65-2302/65-2303 Toxic Detector • 17
CAUTION:For all gases except ClO2: Allow the replacement detector to warm up for 15
minutes before you continue with the next step.
For ClO2: Allow the replacement detector to warm up for 2-3 hours before you
continue with the next step.
11. Calibrate the replacement detector as described in “Calibration” on page 18.
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 toxic detector applications.
Unless experience in a particular application dictates otherwise, RKI Instruments, Inc.
recommends a calibration frequency of every 3 months for the toxic detector.
If an application is not very demanding, for example detection in a clean, temperature
controlled environment where toxic gas is not normally present, 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 or if
toxic gas is often present, then more frequent calibration than every 3 months may be
necessary.

18 • 65-2302/65-2303 Toxic Detector
Calibration
This section describes how to calibrate the toxic detector. It includes procedures to prepare for
calibration, set the fresh air 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.
WARNING: RKI Instruments, Inc. recommends that you dedicate a regulator for use with
chlorine (Cl2) gas and that you do not use that dedicated regulator for any
other gases, particularly hydrogen sulfide (H2S).
WARNING: Not using the recommended calibration cup and sample flowrate will result in
an inaccurate calibration. See“Parts List” on page 20 for the required
calibration cup and regulator.
Special Note About Calibrating a ClO2Detector
RKI Instruments, Inc. recommends using a ClO2generator to set the ClO2detector’s response
reading. The flow rate on the generator needs to be set to 0.5 LPM and RKI Instruments, Inc.
recommends that 0.5 ppm ClO2be used. If a ClO2generator is used for calibration, the steps
related to the use of a calibration gas cylinder in the instructions below can be disregarded.
Preparing for Calibration
CAUTION:For all gases except ClO2: Confirm that the detector has been running for 15
minutes before performing a calibration.
For ClO2: Confirm that the detector has been running for 2-3 hours before
performing a calibration.
1. Screw the calibration cup onto the bottom of the 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 toxic detector is in a fresh air environment, you do not need
to apply zero air to the detector before adjusting the fresh air reading.
4. Put the controller into its calibration program. See the controller operator’s manual for
instructions to enter the calibration program.

65-2302/65-2303 Toxic Detector • 19
Setting the Zero (Fresh Air) Reading
1. Follow the instructions 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 fresh air 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.
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 toxic gas cylinder. If necessary to fit
the calibration toxic gas cylinder, change the regulator.
Setting the Response Reading (Span)
1. Follow the directions in the controller operator’s manual for setting the response (span)
reading.
2. For toxic gas cylinders (like Cl2, NH3, etc.), 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 (or start the flow of gas from a generator).
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, turn the regulator’s on/off knob clockwise to turn it off
(or stop the flow of gas from a generator).
6. Unscrew the regulator from the cylinder.
7. Unscrew the calibration cup from the detector. Make sure that you do not loosen the
detector housing cap when you unscrew the calibration cup.
NOTE: For convenience, leave the regulator and calibration cup connected by the sample
tubing.

20 • 65-2302/65-2303 Toxic 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.
3. Store the components of the calibration kit in a safe and convenient place.
Parts List
Table 2 lists replacement parts and accessories for the toxic detector.
Table 2: Parts List
Part Number Description
06-1283RK Calibration kit sample tubing, 3 foot Teflon w/flexible tubing on ends
07-0039RK Detector housing cap gasket
18-0400RK-01 Junction box with rubber spacers
33-0157RK VersaporR membrane for plug-in sensor face
65-2051-01 Replacement plug-in sensor, 0 - 3.00 ppm, 0 - 5.00 ppm, and 0 - 10.0 ppm Cl2, with
membrane
65-2052-01 Replacement plug-in sensor, 0 - 1.00 ppm, 0 - 3.00 ppm, and 0 - 5.00 ppm ClO2, with
membrane
65-2053-01 Replacement plug-in sensor, 0 - 500 ppm NH3, with membrane
65-2054-01 Replacement plug-in sensor, 0 - 75 ppm, 0 - 100 ppm, and 0 - 200 ppm NH3, with
membrane
65-2302-CL2-3 Replacement detector assembly, Cl2, 0 - 3.00 ppm range (includes plug-in sensor)
65-2302-CL2-5 Replacement detector assembly, Cl2, 0 - 5.00 ppm range (includes plug-in sensor)
65-2302-CL2-10 Replacement detector assembly, Cl2 , 0 - 10.0 ppm range (includes plug-in sensor)
65-2302-CLO2-1 Replacement detector assembly, ClO2 , 0 - 1.00 ppm range (includes plug-in sensor)
65-2302-CLO2-3 Replacement detector assembly, ClO2 , 0 - 3.00 ppm range (includes plug-in sensor)
65-2302-CLO2-5 Replacement detector assembly, ClO2 , 0 - 5.00 ppm range (includes plug-in sensor)
65-2302-HCN-15 Replacement detector assembly, HCN, 0 - 15 ppm range (includes plug-in sensor)
65-2302-NH3-1 Replacement detector assembly, NH3, 0 - 100 ppm range (includes plug-in sensor)
65-2302-NH3-2 Replacement detector assembly, NH3, 0 - 200 ppm range (includes plug-in sensor)