RKI Instruments 35-3001-05 Series User manual

www.rkiinstruments.com
35-3001-05-XX
Carbon Dioxide Sample-Draw Detector
Operator’s Manual
Part Number: 71-0413
Revision: A
Released: 6/20/19

35-3001-05-XX CO2 Sample-Draw 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
6 and 12 months, but can be required more often or less often
based on your usage.

35-3001-05-XX CO2 Sample-Draw Detector
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

35-3001-05-XX CO2 Sample-Draw Detector
Table of Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
External Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Internal Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mounting the Carbon Dioxide Sample-Draw Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Connecting the Sample Lines to the Sample-Draw Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Wiring the Carbon Dioxide Sample-Draw Detector to a Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Start Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Introducing Incoming Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Preventive Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Replacing Components of the Carbon Dioxide Sample-Draw Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Adjusting the Low Flow Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Removing the Particle Filter’s Tubing Stub, if Necessary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Calibration Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Preparing for Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Setting the Zero Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Setting the Response Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Returning to Normal Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

35-3001-05-XX CO2 Sample-Draw Detector • 5
Overview
This operator’s manual describes the 35-3001-05-XX carbon dioxide sample-draw detector. This manual
also describes how to install, start up, maintain, and calibrate the sample-draw detector when using it with a
gas monitoring controller. A parts list at the end of this manual lists replacement parts and accessories for the
sample-draw detector.
Specifications
Table 1 lists specifications for the carbon dioxide sample-draw detector. See the controller Operator’s
Manual for information specific to the controller.
WARNING: When using the 35-3001-05-XX, you must follow the instructions and warnings in this
manual to assure proper and safe operation of the 35-3001-05-XX and to minimize the
risk of personal injury. Be sure to maintain and periodically calibrate the 35-3001-05-XX
as described in this manual.
Table 1: Specifications
Target Gas Carbon Dioxide (CO2)
Detection Range 35-3001-05-02: 0 - 5,000 ppm (parts per million)
35-3001-05-03: 0 - 5% volume
35-3001-05-05: 0 - 50% volume
35-3001-05-10: 0 - 100% volume
Input Power 24 VDC Nominal (18.5 VDC - 30 VDC)
Construction (housing) Fiberglass/polyester (NEMA 4X)
Dimensions 8.5 in. H x 6.5 in. W x 4.25 in. D
Weight 4.5 lbs.
Sampling Method Sample-draw
Sample Flow 3.0 SCFH typical, with no inlet or exhaust line
Flow to Sensor 1.0 SCFH (nominal)
Low Flow Setpoint 0.6 ± 0.1 SCFH
Maximum Recommended Inlet/
Exhaust Line Length for
1/4” O.D. x 1/8” I.D. Tubing
Inlet Exhaust
100 feet 0 feet
50 feet 50 feet
Maximum Recommended Inlet/
Exhaust Line Length for
1/4” O.D. x 0.170” I.D. Tubing
Inlet Exhaust
100 feet 100 feet
Response Time 90% in 30 seconds
Accuracy ± 5% of reading or ± 2% of full scale (whichever is greater)

6 • 35-3001-05-XX CO2 Sample-Draw Detector
Description
This section describes the components of the carbon dioxide sample-draw detector.
Figure 1: Carbon Dioxide Sample-Draw Detector Component Location
Oxygen
Sensor
Terminal
Strip
Pump
Mounting
Foot, 4X
_
O
X
Y
G
E
N
B
+
W
OXY
+ RS
IR CO2
Flow Block
IR CO2
Sensor PCB
BG
Detector/Amp
Terminal Strip
(Factory Wired)
++
AMP AMP 2
S
Sensor Flow
Control Valve
Fail LED
Pilot LED
Pump Reset
Switch
Flowmeter
Pressure Switch
Adjustment Screw
(behind PCB)
R BG
Interconnect
Terminal
Strip
OXY
GW
+
+
AMP 1
S
+S
AMP 2
This End To
Inlet Fitting
Flowmeter Circuit
Board Connector
Pump Connector
LEL/ IR
W
ParticleFilter
LEL/ IR
W
3/4" Conduit Hub
IR CO2
Sensor
(inside block)
Exhaust
Fitting
Inlet
Fitting EXHAUST
INLET
Hydrophobic
Filter

35-3001-05-XX CO2 Sample-Draw Detector • 7
External Components
This section describes the sample-draw detector’s external components.
Housing
The sample-draw detector’s fiberglass housing is weather- and corrosion-resistant. It is suitable for
installation where general purpose equipment is in use.
The housing door is hinged on the left side and is secured by two latches on the right side. The flowmeter
and status LEDs are visible through a window in the housing door.
Four mounting feet are attached to the back of the housing (one at each corner). Use the mounting feet to
install the housing to a vertical surface.
Sample Fittings
The sample fittings are located on the left side of the bottom of the housing. The inlet fitting is near the front
of the housing and the exhaust fitting is near the back of the housing. The sample fittings accept 1/4 in. rigid
tubing. See the Installation section on page 10 to connect tubing to the sample fittings.
Particle Filter
A particle filter with a tubing stub on one end is shipped with the instrument but it is not factory installed. If
the particle filter is installed directly to the inlet fitting, the tubing stub must be used. If the particle filter is
installed somewhere else, like at the end of the inlet line, the tubing stub can be used or removed.
Conduit Hub
One 3/4” conduit hub is located on the right side of the bottom of the housing. It is used for routing wiring
into the housing by using conduit or an appropriate cable bushing.
Internal Components
This section describes the sample-draw detector’s internal components (see Figure 1). Figure 2 illustrates
how the gas sample moves through the flow system.
Figure 2: Carbon Dioxide Sample-Draw Detector Flow Diagram
Pump
IR CO2
Sensor
Flowmeter
Particle Filter
Flowmeter PCB
Exhaust Pressure Switch
Hydrophobic Filter
Inlet Restrictor
Sensor
Flow
Control
Valve

8 • 35-3001-05-XX CO2 Sample-Draw Detector
Main Circuit Board
The main circuit board includes the detector/amp terminal strip, interconnect terminal strip, oxygen sensor
terminal strip, pump connector, and flowmeter circuit board connector (see Figure 1).
Detector/Amp Terminal Strip
The detector/amp terminal strip is the upper twelve-point terminal strip in the bottom right corner of the
main circuit board. Use the detector/amp terminal strip to connect the carbon dioxide sensor to the main
circuit board.
NOTE: The carbon dioxide sensor is factory-wired to the main circuit board. See the “Installation” section
on page 10 for all wiring procedures related to the sample-draw detector.
Interconnect Terminal Strip
The interconnect terminal strip is the lower twelve-point terminal strip in the bottom right corner of the main
circuit board. Use the interconnect terminal strip to connect the sample-draw detector to a controller.
Oxygen Sensor Terminal Strip
The oxygen sensor terminal strip is a two-point terminal strip in the upper right corner of the main circuit
board. This terminal strip is not used in this version of the sample-draw detector.
Pump Connector
The pump connector is the two-point connector below the oxygen terminal strip in the upper right corner of
the main circuit board. Use the pump connector to connect the pump to the main circuit board.
NOTE: The pump is factory-wired to the main circuit board. See “Installation” on page 10 for all wiring
procedures related to the sample-draw detector.
Flowmeter Circuit Board Connector
The flowmeter circuit board connector is a six-position connector in the upper left corner of the main circuit
board. Use the flowmeter circuit board connector to connect the flowmeter circuit board to the main circuit
board.
NOTE: The flowmeter circuit board is factory wired to the main circuit board. See “Installation” on
page 10 for all wiring procedures related to the sample-draw detector.
Flowmeter Circuit Board
The flowmeter circuit board is mounted to the left side of the main circuit board using standoffs. It includes
the flowmeter, sensor flow control valve, status LEDs, pressure switch, and pump reset switch.
Flowmeter
The flowmeter is mounted to the right side of the flowmeter circuit board. You can see it through the
window in the door. A ball in the flowmeter column indicates the flow rate to the sensor. The flowmeter
measures the flow in the range 0.2 to 2.0 SCFH (Standard Cubic Feet per Hour). The optimum flow rate is
1.0 SCFH.
Sensor Flow Control Valve
The sensor flow control valve is mounted to the flowmeter circuit board above the flowmeter. The sensor
flow control valve adjusts the flow rate to the detector. Turn the valve’s knob counterclockwise to increase
the flow and clockwise to decrease the flow.

35-3001-05-XX CO2 Sample-Draw Detector • 9
Status LEDs
Two status LEDs are above the flowmeter. They are also visible through the window in the housing door.
The green Pilot LED is on when the sample-draw detector is receiving power from the controller. The red
Fail LED is on when the sample flow rate is below the low flow level.
Pressure Switch
The pressure switch is mounted to the back of the flowmeter circuit board. The pressure switch monitors the
flow rate of the incoming gas sample.
If the flow rate falls below the preset low flow level, the pressure switch causes the Fail LED to turn on and
interrupts the signal from the detector. The interrupted detector signal causes a fail condition at the
controller. The low flow level is factory-set at 0.6 SCFH (±0.1 SCFH). See “Adjusting the Low Flow
Setting” on page 18 to adjust this setting.
Pump Reset Switch
The pump reset switch is located to the left of the status LEDs. When a low flow condition occurs, the pump
will be shut off. To reset the low flow condition and start the pump again, press and hold the pump reset
switch for about 2 seconds, then release.
Hydrophobic Filter
The hydrophobic filter is located toward the bottom left of the main circuit board. The filter prevents
particulates and water in the incoming gas sample from damaging the flow and detection systems. Replace
the filter when it appears dirty, discolored, or clogged.
Pump
The pump is mounted to the right side of the main circuit board. The pump pulls the gas sample into the
sample-draw detector. The pump operates on 24 VAC, which is generated from the 24 VDC supplied by the
controller.
IR Carbon Dioxide Sensor/IR Carbon Dioxide Sensor PCB
The carbon dioxide sensor is an infrared type plug-in detector. The carbon dioxide sensor is installed in the
IR carbon dioxide flow block and the IR carbon dioxide flow block is mounted to the middle of the main
circuit board. A small circuit board, the IR carbon dioxide sensor PCB, with a 4-wire cable mates to the IR
carbon dioxide sensor and retains it in the flow block. The cable is wired to the main PCB. The IR carbon
dioxide sensor PCB allows you to replace the sensor without disconnecting the wiring.

10 • 35-3001-05-XX CO2 Sample-Draw Detector
Installation
This section describes procedures to mount the sample-draw detector in the monitoring environment and
wire the sample-draw detector to a controller.
Mounting the Carbon Dioxide Sample-Draw Detector
1. Select the mounting site. Consider the following when you select the mounting site:
• Is there enough room to open the housing door and make wiring and tubing connections at the
bottom of the housing?
• Make sure there is sufficient room to perform start-up, maintenance, and calibration procedures.
• Are the flowmeter and status LEDs visible?
Figure 3: Outline and Mounting Dimensions
Ø.30x.50(4X)MOUNTING
.78
1.13
.40
Pilot Fail
.85
.80
4.50
NOTE: Housing is4.3 inchesdeep
8.88
4.00
6.50
35-3001
www.rkiinstruments.com
Sample Drawing
GasDetector
8.50

35-3001-05-XX CO2 Sample-Draw Detector • 11
2. Close and latch the housing door.
NOTE: The sample-draw detector is shipped with the mounting feet “tucked under” the housing to protect
the mounting feet during shipment.
3. Slightly loosen the screw that secures the mounting foot to the housing, then rotate the mounting foot
180 degrees (see Figure 3).
4. Tighten the screw that secures the mounting foot to the housing.
5. Repeat steps 3 and 4 for the remaining three mounting feet.
6. Position the sample-draw housing on a vertical surface at eye level (4 1/2 to 5 feet from the floor).
7. Insert 1/4 inch screws through the slots in the mounting feet to secure the housing to the mounting
surface.
Connecting the Sample Lines to the Sample-Draw Detector
See Figure 5 for the fitting layout.
Installing the Inlet Line with Particle Filter Connected to the Inlet Fitting
1. Loosen the nut on the inlet fitting until 3 threads are visible.
2. Push the particle filter’s tubing stub into the inlet fitting until it stops. Be sure the arrow on the particle
filter is pointing toward the inlet fitting.
3. Hand tighten the nut on the inlet fitting so the ferrules clamp on the tubing. If the tube nut is removed,
see Figure 5 for the arrangement of the fitting components.
4. Connect a length of sample tubing to the other side of the particle filter and route it to the sampling area.
1/4” O.D. rigid polypropylene, Teflon, or flexible polyurethane tubing may be used. RKI Instruments,
Inc. recommends using either 1/4” O.D. x 1/8” I.D. or 1/4” O.D. x 0.170” I.D. tubing based on your
length requirements. See “Specifications” on page 5 for maximum tubing lengths based on tubing size.
CAUTION: If you use flexible sample tubing (polyurethane is acceptable), use an appropriate insert if
necessary to provide support to the tubing and ensure a good seal when connecting to the
flexible stub on the filter.
CAUTION: Avoid loops or slumps in the incoming sample line. To reduce response time, keep the
incoming sample line as short as possible.
Installing the Inlet Line without Particle Filter Connected to the Inlet Fitting
1. Loosen the nut on the inlet fitting until 3 threads are visible.
2. Push 1/4” O.D. rigid polypropylene or rigid Teflon sample tubing into the fitting until it stops. Flexible
polyurethane tubing may be used with an appropriate insert. RKI Instruments, Inc. recommends using
either 1/4” O.D. x 1/8” I.D. or 1/4” O.D. x 0.170” I.D. tubing based on your length requirements. See
“Specifications” on page 5 for maximum tubing lengths based on tubing size.
CAUTION: If you use flexible sample tubing (polyurethane is acceptable), use an appropriate insert to
seal the connection between the tubing and the inlet fitting.
3. Hand tighten the nut on the inlet fitting so the ferrules clamp on the tubing. If the tube nut is removed,
see Figure 5 for the arrangement of the fitting components.

12 • 35-3001-05-XX CO2 Sample-Draw Detector
4. Route tubing from the inlet fitting to the sample area. See “Specifications” on page 5 for maximum
tubing lengths based on tubing size.
CAUTION: Avoid loops or slumps in the incoming sample line. To reduce response time, keep the
incoming sample line as short as possible.
5. If desired, install the particle filter onto the end of the inlet line. Be sure the arrow on the particle filter is
pointed toward the inlet line.
Installing the Exhaust Line
1. Loosen the nut on the exhaust fitting until 3 threads are visible.
2. Push 1/4” O.D. rigid polypropylene or rigid Teflon sample tubing into the fitting until it stops. Flexible
polyurethane tubing may be used with an appropriate insert. RKI Instruments, Inc. recommends using
either 1/4” O.D. x 1/8” I.D. or 1/4” O.D. x 0.170” I.D. tubing based on your length requirements. See
“Specifications” on page 5 for maximum tubing lengths based on tubing size.
CAUTION: If you use flexible sample tubing (polyurethane is acceptable), use an appropriate insert to
seal the connection between the tubing and the inlet fitting.
3. Hand tighten the nut on the exhaust fitting so the ferrules clamp on the tubing. If the tube nut is
removed, see Figure 5 for the arrangement of the fitting components.
4. Route the opposite end of the tubing to an open area where the sample can safely disperse or to an
exhaust duct. See “Specifications” on page 5 for maximum tubing lengths based on tubing size.
Wiring the Carbon Dioxide Sample-Draw Detector to a Controller
WARNING: Always verify that the controller is off and that power to the controller is off before you
make wiring connections.
1. Turn off the controller.
2. Turn off power to the controller.
3. Unlatch and open the housing door of the sample-draw detector.
4. Guide a six-conductor, shielded cable or six wires in conduit through the conduit hub at the bottom of
the sample-draw housing. A minimum of 18 AWG wire is recommended.
5. Connect the cable to the sample-draw detector’s interconnect terminal strip as shown in Figure 4.
6. Close and latch the housing door of the sample-draw detector.
CAUTION: If using shielded cable, leave the cable shield’s drain wire insulated and disconnected at the
sample-draw detector. You will connect the opposite end of the drain wire at the controller.
7. Route the cable or wires in conduit leading from the sample-draw detector through one of the conduit
hubs at the controller.

35-3001-05-XX CO2 Sample-Draw Detector • 13
8. Connect the wires to the applicable detector/transmitter terminal strip at the controller as shown in
Figure 4. Refer to the controller operator’s manual and the controller detector head specification sheet
for the 35-3001-05-XX for detector/terminal strip connections specific to the controller.
Figure 4: Wiring the Sample-Draw Detector 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.
Green
Black
Red
White
Not Used on
ThisVersion
PATS201
AMP 2 LEL/IR
OXY
LEL/IR
PATS101PATS101PATS201
OXY
AMP 1
AMP 1
AMP 2
Black
White
+ 24 VDC
Controller Detector/
Transmitter Terminal
Strip, LEL Detector
Terminals
- (DC Ground)
Red
Green
Controller Detector/
Transmitter Terminal
Strip Terminals
ToIR CO2
Sensor

14 • 35-3001-05-XX CO2 Sample-Draw Detector
Start Up
This section describes procedures to start up the sample-draw detector and place the sample-draw detector
into normal operation.
Introducing Incoming Power
1. Complete the installation procedures described earlier in this manual.
2. Verify that the wiring is correct and secure. Refer to the controller operator’s manual for connections at
the controller.
3. Turn on or plug in the power to the controller, then turn on the controller.
4. Verify that the sample-draw detector’s Pilot LED is on.
5. Verify that the controller is on and operating properly. Refer to the controller operator’s manual.
6. Verify that the flowmeter indicates a flow rate of approximately 1.0 SCFH. If necessary, use the sensor
flow control valve to adjust the flow rate. Turn the valve’s knob counterclockwise to increase the flow
and clockwise to decrease the flow.
NOTE: The following step tests for leaks in the sample line. This test will cause a low flow condition at
the sample-draw detector and a fail condition at the controller. Be sure to put the controller into its
calibration program or disable external alarms before performing this test.
7. Verify that the incoming sample line is not leaking. To test the sample line, press and hold the reset
switch and plug the open end of the sample line with your thumb. If the flowmeter ball drops to the
bottom of the flowmeter, the incoming sample line is not leaking.
8. Remove your thumb from the sample line, release the reset switch, and verify the flowmeter returns to a
normal flow rate.
9. Enable alarms or place the controller in normal operation.
CAUTION: Allow the sample-draw detector to warm up for 5 minutes before you continue with the next
section, “Setting the Zero Reading.”
Setting the Zero Reading
Since there is a background of CO2 in air of typically 300 - 600 ppm (0.03 - 0.06% volume), it is necessary
to use a calibration kit with a 100% nitrogen cylinder to set the zero signal for the
0 - 5,000 ppm and 0 - 5% volume versions. Fresh air can be used to set the zero signal for the
0 - 50% and 0 - 100% volume versions.
1. Screw the demand flow regulator into the 100% nitrogen calibration cylinder.
2. Connect the calibration tubing from the demand flow regulator to the inlet fitting. Gas will begin to
flow.
3. Allow the sample-draw detector to draw sample for one minute.
4. Verify a reading of 0% vol on the controller display screen for the applicable channel.
If the display reading is 0% vol, start up is complete. The sample-draw detector is in normal operation.
If the display reading is not 0% vol, continue with step 5.
5. Perform a zero operation at the controller. See “Setting the Zero Reading” on page 20 and the controller
operator’s manual for instructions to perform a zero operation.
6. Remove the calibration tubing from the inlet fitting, then reconnect the sample tubing to the inlet fitting.

35-3001-05-XX CO2 Sample-Draw Detector • 15
Maintenance
This section describes maintenance procedures. It includes preventive maintenance procedures. This section
also includes procedures to troubleshoot the sample-draw detector, replace components of the sample-draw
detector, adjust the low flow setting, and remove the particle filter’s tubing stub.
Preventive Maintenance
This section describes a preventive maintenance schedule to ensure the optimum performance of the sample-
draw detector. It includes daily and biannual procedures.
Daily Visual Checks
1. Verify that the Pilot LED is on.
2. Verify that the flowmeter indicates a flow rate of approximately 1.0 SCFH. If necessary use the sensor
flow control valve to adjust the flow rate to 1.0 SCFH. Turn the valve’s knob counterclockwise to
increase the flow and clockwise to decrease the flow.
3. Verify a display reading at the controller of the background concentration of CO2. Typical background
concentrations of CO2 vary from about 300 to 600 ppm (0.03 - 0.06% volume) depending on location.
The 0 - 5,000 ppm and 0 - 5% volume ranges will show a reading in fresh air. The 0 - 50% and 0 - 100%
volume ranges should not show a reading in fresh air. Investigate significant changes in the display
reading.
Biannual Calibration
Calibrate the sample-draw detector as described in “Calibration” on page 20.
Troubleshooting
The troubleshooting guide describes symptoms, probable causes, and recommended action for problems you
may encounter with the sample-draw detector.
NOTE: This troubleshooting guide describes sample-draw detector problems only. See the controller
Operator’s Manual if the controller exhibits any problems.
Fail Condition
Symptoms
• The sample-draw detector’s Fail LED is on.
• The monitoring device is operating properly but indicates a reading well below zero.
Probable causes
• The sample-draw detector’s flow rate is too low because of an obstructed sample line, failed pump, etc.
• The sample-draw detector is malfunctioning.
• The sensor wiring is disconnected or misconnected.
Recommended action
1. At the sample-draw detector, set the correct flow rate with the sensor flow control valve.
2. If you cannot set the correct flow rate, check the sample lines for obstructions or kinks.
3. Verify that the sensor wiring is correct and secure. “Wiring the Carbon Dioxide Sample-Draw Detector
to a Controller” on page 12 describes sensor wiring connections.
4. Calibrate the sample-draw detector as described in “Calibration” on page 20.

16 • 35-3001-05-XX CO2 Sample-Draw Detector
5. If the fail condition continues, replace the sensor as described in “Replacing the Infrared Carbon
Dioxide Sensor” on page 16.
6. If the fail condition continues, contact RKI Instruments, Inc. 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 sensor requires frequent calibration.
Probable causes
• The calibration cylinder is low, out-dated, or defective.
• If a demand flow regulator calibration kit is used, the demand flow regulator is not functioning properly.
• The sample-draw detector’s flow rate is too low because of an obstructed sample line, failed pump, etc.
• The sample-draw detector is malfunctioning.
Recommended action
1. Verify that the calibration cylinder contains an adequate supply of a fresh test sample.
2. If a demand flow regulator calibration kit is used, use a different demand flow regulator to determine if
the original one is functioning properly.
3. If necessary, set the correct flow rate with the sensor flow control valve.
4. If you cannot set the correct flow rate, check the sample line for obstructions or kinks.
5. If the calibration/response difficulties continue, replace the 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 Carbon Dioxide Sample-Draw Detector
This section includes procedures to replace the sensor, hydrophobic filter, and particle filter.
Replacing the Infrared Carbon Dioxide Sensor
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Unscrew and remove the four screws that secure the IR carbon dioxide sensor PCB, then lift the IR
carbon dioxide sensor PCB and sensor off of the flow block.
There is a gasket at the bottom of the flow block. Be sure the gasket stays in place.
5. Unplug the sensor from the IR carbon dioxide sensor PCB.
6. Verify that you are using the correct replacement sensor, then plug the sensor into the IR carbon dioxide
sensor PCB.
7. Place the sensor and sensor PCB in the carbon dioxide sensor cavity.
8. Secure the sensor PCB on the flow block with the four screws you removed in step 4.
9. Close and latch the housing door.
10. Turn on power to the controller.
11. Turn on the controller.
CAUTION: Allow the replacement sensor to warm up for 5 minutes before you continue.

35-3001-05-XX CO2 Sample-Draw Detector • 17
12. Calibrate the replacement sensor as described in “Calibration” on page 20.
Replacing the Hydrophobic Filter
1. Turn off the controller.
2. Turn off power to the controller.
3. Open the housing door of the sample-draw detector.
4. Disconnect the filter from the rubber elbows on each end of the filter, then remove the filter from the
sample-draw detector.
5. Install the new filter. Be sure the side of the filter marked “INLET” is connected to the elbow that is
connected to the inlet fitting.
6. Turn on power to the controller.
7. Turn on the controller.
8. Verify that the flow rate is approximately 1.0 SCFH, then close the housing door.
Replacing the Particle Filter
1. Turn off the controller.
2. Turn off power to the controller.
3. If the particle filter is installed at the inlet fitting:
1. Disconnect the tubing routed to the sampling area, if installed, from the particle filter.
2. Disconnect the particle filter from the tubing stub.
3. Install the new particle filter onto the tubing stub. Be sure the arrow on the particle filter is pointing
toward the inlet fitting.
4. Reinstall the tubing routed to the sampling area.
4. If the particle filter is installed at the end of the inlet line:
1. Remove the particle filter from the tubing stub.
2. Install the new particle filter onto the tubing stub. Be sure the arrow on the particle filter is pointing
toward the inlet line.
5. Turn on power to the controller.
6. Turn on the controller.

18 • 35-3001-05-XX CO2 Sample-Draw Detector
Adjusting the Low Flow Setting
NOTE: Adjusting the low flow setting will cause a low flow alarm at the sample-draw detector and a fail
alarm at the controller. Be sure to put the controller into its calibration program or disable external
alarms before performing this test.
The factory-set low flow setting is 0.6 SCFH (±0.1). To adjust the low flow setting:
1. Use the sensor flow control valve to set the flow to 0.6 SCFH. Turn the valve’s knob counterclockwise
to increase the flow and clockwise to decrease the flow.
If the sample-draw detector goes into low flow alarm before you can adjust the flow down to 0.6 SCFH,
adjust the pressure switch adjustment screw 1/4 turn clockwise, then attempt to set the flow again.
Repeat this step until you are able to adjust the flow to 0.6 SCFH.
NOTE: The pressure switch adjustment screw is accessible through a circular cutout in the flowmeter
circuit board.
2. Slowly turn the pressure switch adjustment screw counterclockwise just until the sample-draw detector
goes into low flow alarm.
3. Turn the sensor flow control valve’s knob counterclockwise to increase the flow until the unit is out of
low flow alarm when the reset button is pressed and released.
4. Decrease the flow very slowly by turning the sensor flow control valve’s knob clockwise and verify that
the low flow alarm is 0.6 SCFH (±0.1).
If the low flow alarm is set too high, turn the pressure switch adjustment screw slightly clockwise.
Repeat steps 3 and 4 if necessary.
5. Use the sensor flow control valve to set the flow to 1.0 SCFH.
6. Make sure the sample-draw detector’s Fail LED is off.

35-3001-05-XX CO2 Sample-Draw Detector • 19
Removing the Particle Filter’s Tubing Stub, if Necessary
A short tubing stub comes factory installed in the particle filter. It is used for connecting the particle filter to
the inlet fitting. If you have installed the particle filter and no longer want it installed, you will need to
remove the particle filter’s tubing stub from the inlet fitting and replace it with tubing.
Figure 5: Inlet Fitting with Tubing Stub
CAUTION: Do not pull the tubing stub downward to remove it.
1. Remove the particle filter from its tubing stub.
2. Unscrew the outside inlet fitting tube nut from the fitting body. The tubing stub should come out with
the tube nut. Be careful not to lose the O-ring that may come out with the tubing stub. If you do lose the
O-ring or if it is damaged, see “Parts List” on page 21 for the spare part number.
3. Push the tubing stub up and out of the front ferrule being careful not to lose the ferrule set. If you do lose
the ferrule set or if it is damaged, see “Parts List” on page 21 for the spare part numbers.
4. Push the new tubing up through the inlet fitting tube nut and replace the ferrule set and the O-ring, if it
came out, in the orientation shown in Figure 5.
5. Screw the inlet fitting tube nut back onto the fitting body. See “Connecting the Sample Lines to the
Sample-Draw Detector” on page 11 for instructions to install a new piece of tubing into the fitting.
Outside of Case
Fitting Body
Front Ferrule
Back Ferrule
1/4" Tube
1/4" Tube
O-ring
Tube Nut
Inside of Case

20 • 35-3001-05-XX CO2 Sample-Draw Detector
Calibration Frequency
Although there is no particular calibration frequency that is correct for all applications, a calibration
frequency of every 6 months is adequate for most infrared combustible gas transmitter applications. Unless
experience in a particular application dictates otherwise, RKI Instruments, Inc. recommends a calibration
frequency of every 6 months.
If an application is not very demanding, for example detection in a clean, temperature controlled
environment where calibration adjustments are minimal at calibration, then a calibration frequency of every
9 to 12 months is adequate.
If an application is very demanding, for example if the environment is not well controlled, then more
frequent calibration than every 6 months may be necessary.
Calibration
This section describes how to calibrate the carbon dioxide sample-draw detector. It includes procedures to
prepare for calibration, set the zero reading, set the response reading, and return to normal operation.
NOTE: This procedure describes calibration using a demand flow regulator.
Preparing for Calibration
1. Follow the instructions in the controller’s operator’s manual for entering calibration mode.
NOTE: If you can verify a fresh air environment, it is not necessary to use the zero air calibration cylinder
to set the zero reading.
2. Screw the regulator into a zero air calibration cylinder.
Setting the Zero Reading
Since there is a background of CO2 in air of typically 300 - 600 ppm (0.03 - 0.06% volume), it is necessary
to use a calibration kit with a 100% nitrogen cylinder to set the zero signal for the
0 - 5,000 ppm and 0 - 5% volume versions. Fresh air can be used to set the zero signal for the
0 - 50% and 0 - 100% volume versions.
1. Screw the regulator into a 100% nitrogen calibration cylinder.
2. Connect the sample tubing from the demand flow regulator to the sample-draw detector’s inlet line.
3. Allow the sample-draw detector to draw sample for one minute.
4. Follow the directions in the controller’s operator’s manual for setting the zero reading.
5. Disconnect the sample tubing from the inlet line.
6. Unscrew the regulator from the 100% nitrogen calibration cylinder.
Setting the Response Reading
1. Screw the regulator into the carbon dioxide calibration cylinder.
2. Connect the sample tubing from the demand flow regulator to the sample-draw detector’s inlet line.
3. Allow the sample-draw detector to draw sample for one minute.
4. Follow the directions in the controller’s operator’s manual for setting the span.