Dwyer Instruments CDT Series User manual

Series CDT and CDTR Duct Mount Carbon Dioxide/
Temperature/Relative Humidity Transmitter
Specications - Installation and Operating Instructions
Bulletin AQ-CDT/CDTR
Series CDT and CDTR Duct Mount Carbon Dioxide/ Temperature/Relative
Humidity Transmitters accurately monitor the CO2concentration and temperature
in schools, ofce buildings, and other indoor environments to help achieve LEED®
certication. For increased sensor life, a single- beam dual-wavelength non-dispersive
infrared (NDIR) sensor is used to automatically correct the measurement in both
occupied and unoccupied buildings against aging effects. The single-beam dual-
wavelength sensor technology provides the highest level of accuracy, compared to
Automatic Baseline Correction methods, which can unintentionally shift the calibration
based on CO2 levels and barometric pressure conditions. In order to achieve a higher
level of accuracy, the Series CDT includes digital barometric pressure adjustment and
the ability to eld-calibrate the sensor.
Universal outputs allow users to select the transmitter output to be 4 to 20 mA, 0 to
5 VDC or 0 to 10 VDC to work with virtually any building management controller. An
optional relay with user adjustable set points can be used to control exhaust fans, open
actuated windows or dampers, or signal a light or horn.
For applications that require visual indication, the Series CDT and CDTR can be
ordered with the Model A-449 remote LCD display that can plug into the mini-connector
port on the internal circuit board. Both the CDT and CDTR can be congured to display
temperature only, CO2only or CO2 and temperature together. The CDTR can also
display relative humidity or CO2 and relative humidity together. Menu items that can
be accessed include: engineering units, relay output set points, display conguration,
transmitter output scaling, ambient barometric pressure and eld calibration of the
transmitter.
Single-beam dual-wavelength sensor advantages:
• Automatically corrects for aging effects in occupied and unoccupied buildings
◦ Perfect for hospitals and manufacturing plants that are occupied 24 hours per
day
• Measures actual unltered light intensity directly
◦ Eliminates error from incorrect assumptions of gas concentration in theoretical
logic assumption methods
INSTALLATION
LEED® is a registered trademark of the U.S. Green Building Council
Disconnect power supply before installation to prevent electrical
shock and equipment damage.
Make sure all connections are in accordance with the job wiring diagram and in
accordance with national and local electrical codes. Use copper conductors only.
Use electrostatic discharge precautions (e.g., use of wrist straps)
during installation and wiring to prevent equipment damage.
Avoid locations where severe shock or vibration, excessive
moisture or corrosive fumes are present.
Do not exceed ratings of this device, permanent damage not
covered by warranty may result.
Upon powering the transmitter, the rmware version will ash on
the display. A warm up period of 30 minutes is required for the
transmitter to adjust to the current CO2 concentration.
Self calibration feature of the transmitter requires exposure to
normal outdoor equivalent carbon dioxide level once every thirty
days.
NOTICE
NOTICE
SPECIFICATIONS
Range: CO2: 0 to 2000 or 0 to 5000 ppm (depending on model); RH: 0 to 100% (for
units congured with humidity output); Temperature: 32 to 122°F (0 to 50°C).
Accuracy: ±40 ppm + 3% of reading (CO2); RH: ±2% (for units congured with
humidity output); Temperature: ± 1°C @ 25°C.
Temperature Dependence: ±8 ppm / °C at 1100 ppm.
Non-Linearity: 16 ppm.
Pressure Dependence: 0.13% of reading per mm of Hg.
Response Time: 2 minutes for 99% step change.
Temperature Limits: 32 to 122°F (0 to 50°C).
Humidity Limits: 10 to 95% RH (non-condensing).
Power Requirements: 16 to 35 VDC / 19 to 28 VAC.
Power Consumption: Average: 2 watts; Peak: 3.75 watts.
Sensor: Single-beam, dual-wavelength NDIR.
Output: Current: 4 to 20 mA (max 500 Ω); Voltage: 0 to 5 VDC or 0 to 10 VDC
(min 500 Ω); Relay: SPST NO 2A @ 30 VDC; RTD or thermistor per r-t curves
(depending on model).
Weight: 5.6 oz (158.8 g).
Agency Approvals: CE.
WARNING
CAUTION
CAUTION
CAUTION
1/8˝
[3.17]
4-25/32˝
[121.44]
4-9/32˝
[108.74] 2-13/16˝
[71.44]
Ø3-5/16˝
[84.14]
11-49/64˝
[298.85]
Ø1-15/64˝
[31.35]
®
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone]
Fax: [phone]
www.dwyer-inst.com
e-mail: [email protected]

MOUNTING
1. Cut hole into duct large enough to insert probe.
2. Attach housing ears to duct using the two self-tapping screws provided.
3. Knock out an opening in the housing and attach an electrical tting to route
electrical wiring. PG11 & PG16 knockouts are molded into the housing.
WIRING
Use maximum 18 AWG wire for wiring to terminals. Refer to Figure 5 for wiring
information.
Selection of Current and Voltage Outputs
Prior to wiring, verify that the current/voltage conguration switches (positions 1 and 2)
are set to the desired output type. Refer to Figure 1 to locate the conguration switches.
See Figure 2 for diagram of the current/voltage selection switches. For voltage output
selection, the output can be 0 to 10 VDC, 0 to 5 VDC, 2 to 10 VDC or 1 to 5 VDC. See
Figure 3 for the type of voltage output selection switches (positions 3 & 4).
Current / Voltage Outputs
The transmitter may be wired for current or voltage output for both carbon dioxide and
temperature. The transmitter can be powered with either 16 to 35 VDC or 19 to 28
VAC. Wire the transmitter according to Figure 4.
Thermistor and RTD Outputs
Thermistor and RTD passive outputs are located on terminals 7 and 8 and do not
require any power. Passive temperature outputs are not polarity sensitive.
Remote Display
Remote display Model A-449 can be used to display the relative humidity, temperature,
and carbon dioxide. The mini USB plug of the remote display plugs into the receptor on
the side of the housing. After a short warm up time, the display will begin to show the
current temperature and carbon dioxide measurements unless congured by the user
to show only temperature or only carbon dioxide.
ACCESSING MENU PARAMETERS
Step 1: To enter the menu structure, press and simultaneously for 5
seconds (display will show RON parameter).
Step 2: Press or to cycle between menu items.
Step 3: Press to edit the value for the displayed menu item (SET will appear on
display).
Step 4: Press or to adjust the value of the menu item.
Step 5: Press to save the changes (SET will disappear).
Step 6: Repeat Steps 2 through 5 for each of the parameters.
Step 7: To exit the menu at any time, press and hold and simultaneously
for 5 seconds or wait 10 seconds without pushing any buttons.
PASSIVE
TEMPERA
TURE
SENSOR
RELAY
CONTACT
POWER
SUPPLY
TEMP OR RH
RECEIVER
CO2
RECEIVER
Figure 4: Active Output Wiring Diagram
Figure 1: Diagram Of Circuit Board
Figure 2: Current/Voltage Output
Selection Jumper (PJ1 And PJ2)
Figure 3: Output Range Selection Jumper
Optional relay can be used as either a dry contact or low voltage
switched circuit up to 2 A at 30 VDC.
NOTICE
DOWN PUSH
BUTTON
CONFIGUATION
SWITCHES TERMINAL
BLOCK
REMOTE DISPLAY
CONNECTOR
UP PUSH BUTTON
ENTER PUSH BUTTON
CO2 CONCENTRATION
OUTPUT SELECTION
TEMPERATURE/
RH OUTPUT SELECTION
VOLTAGE CURREN
TVO
LTAGE CURRENT
0-10 V
0-20 mA
2-10 V
4-20 mA
0-5 V
0-10 mA
1-5 V
2-10 mA

Relay on set point
Sets the CO2 concentration which the optional relay is energized.
Low limit: 0 PPM
Factory setting: 1000 PPM
High limit: 2000/5000 PPM (depending on model)
Relay off set point
Sets the CO2 concentration which the optional relay is de-energized. Setting
value lower than RON provides direct action for detecting high concentrations
of CO2. Setting value higher than RON provides indirect action for detecting
low concentrations of CO2. or on the LCD display will be lit to
indicate when the relay is energized.
Low limit: 0 PPM
Factory setting: 950 PPM
High limit: 2000/5000 PPM (depending on model)
Display conguration
Determines the LCD display conguration during normal operation. The LCD
display can indicate the CO2 concentration, temperature, relative humidity
(CDTR only) and CO2 concentration combined with temperature or relative
humidity (CDTR only).
CH CO
2 concentration and relative humidity (CDTR only)
CT CO
2concentration and temperature
C CO2concentration only
T Temperature only
H Relative humidity only (CDTR only)
Units selection
Temperature and barometric pressure measurements can be displayed in US
engineering units or SI engineering units. The factory default is to display US
engineering units.
US units °F for temperature and in Hg for barometric pressure
SI units °C for temperature and hPa for barometric pressure
CO2 low output range
Sets the CO2 concentration for the lowest output (4 mA or 0 VDC).
Low limit: 0 PPM
Factory setting: 0 PPM
High limit: 2000/5000 PPM (depending on model)
CO2 high output range
Sets the CO2 concentration for the highest output (20 mA, 5 VDC or 10 VDC).
When COH is set above COL, the transmitter is direct acting and the output
will increase with an increase in CO2 level. When COH is below COL, the
transmitter is reverse acting and the output will increase with a decrease in
CO2 level.
Low limit: 0 PPM
Factory setting: 2000/5000 PPM (depending on model)
High limit: 2000/5000 PPM (depending on model)
RON
ROF
DSP
UNI
COL
COH
TOL
TOH
HOL
HOH
BAR
CAL
Temperature low output range (CDT with active temperature only)
Sets the temperature for the lowest output (4 mA or 0 VDC).
Low limit: 32.0°F / 0.0°C
Factory setting: 32.0°F / 0.0°C
High limit: 122.0°F / 50.0°C
Temperature high output range (CDT with active temperature only)
Sets the temperature for the highest output (20 mA, 5 VDC or 10 VDC).
When TOH is set above TOL, the transmitter is direct acting and the output
will increase with an increase in temperature. When TOH is below TOL, the
transmitter is reverse acting and the output will increase with a decrease in
temperature.
Low limit: 32.0°F / 0.0°C
Factory setting: 122.0°F / 50.0°C
High limit: 122.0°F / 50.0°C
Humidity low output range (CDTR only)
Sets the temperature for the lowest output (4 mA or 0 VDC).
Low limit: 0.0%
Factory setting: 0.0%
High limit: 100.0%
Humidity high output range (CDTR only)
Sets the temperature for the highest output (20 mA, 5 VDC or 10 VDC).
When HOH is set above HOL, the transmitter is direct acting and the output
will increase with an increase in temperature. When HOH is below HOL, the
transmitter is reverse acting and the output will increase with a decrease in
temperature.
Low limit: 0.0%
Factory setting: 100.0%
High limit: 100.0%
Barometric pressure
Sets the typical barometric pressure for the location where the transmitter is
mounted. The factory setting is for standard pressure at sea level. Adjusting the
barometric pressure gives a more accurate measurement, especially at higher
elevations. Refer to the elevation charts in Figure 9 for typical barometric
pressures at a given elevation.
Low limit: 20.0 in Hg / 600 hPa
Factory setting: 29.9 in Hg / 1013 hPa
High limit: 32.0 in Hg / 1100 hPa
Calibration
Calibrates the carbon dioxide sensor to a known gas value. Read calibration
instructions before using this feature. Hold for 5 seconds.
Menu Descriptions

©Copyright 2019 Dwyer Instruments, Inc. Printed in U.S.A. 1/19 FR# 443800-10 Rev. 8
CALIBRATING SENSOR
Step 1: Remove the cover as shown in Figure 1.
Step 2: Slide the calibration tubing through the slots on the back plate and attach to
one of the nipples on the CO2 sensor (See Figure 7).
Step 3: Carefully re-attach the cover to the back plate without pinching the tubing
between the back plate and the cover.
Step 4: Follow the steps in the accessing parameter section to access the
calibration parameter (CAL).
Step 5: Press the button.
Step 6: Flow zero reference gas at 0.3 SLPM for 5 minutes.
Step 7: Press and hold the button for 3 seconds.
Step 8: Flow the full scale reference gas at 0.3 SLPM for 5 minutes.
Step 9: Press and hold the button for 3 seconds.
Step 10: Exit the parameter menu.
Step 11: Remove cover as shown in Figure 1.
Step 12: Remove tubing from sensor and re-attach the gas nipple cover to the sensor.
Step 13: Re-attach the cover to the back plate.
MAINTENANCE/REPAIR
Upon nal installation of the Series CDT/CDTR, no routine maintenance is required.
The Series CDT/CDTR is not eld serviceable and should be returned if repair is
needed. Field repair should not be attempted and may void warranty.
WARRANTY/RETURN
Refer to “Terms and Conditions of Sales” in our catalog and on our website. Contact
customer service to receive a Return Goods Authorization number before shipping the
product back for repair. Be sure to include a brief description of the problem plus any
additional application notes.
Series CDT -2 D4 4 -RLY Example: CDT-2D44-LCD
Range 2
5
0 to 2000 ppm CO2 range
0 to 5000 ppm CO2 range
Conguration D Duct
CO2 Output 4 4 to 20 mA / 0 to (5 or 10) VDC
Temperature
Output
0
4
A
B
C
D
E
F
None
4 to 20 mA / 0 to (5 or 10) VDC
10 KΩ NTC thermistor type III
10 KΩ NTC thermistor type II
3 KΩ NTC thermistor
Pt100 Ω RTD
Pt1000 Ω RTD
20 KΩ NTC thermistor
Options RLY Relay
US Customary Units
ft in Hg
0
400
800
1200
1600
2000
2400
2800
3200
3600
4000
4400
4800
5200
5600
6000
6400
6800
7200
7600
8000
8400
8800
9200
9600
10000
29.92
29.50
29.10
28.69
28.29
27.90
27.51
27.13
26.76
26.39
26.02
25.66
25.30
24.95
24.60
24.26
23.93
23.60
23.27
22.94
22.63
22.31
22.00
21.70
21.40
21.40
SI Units
mhPa
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
2400
2500
1013
1002
990
979
968
957
946
935
924
914
904
893
883
873
863
853
844
834
824
815
806
797
787
779
770
761
Series CDTR -2 D4A4 -RLY Example: CDTR-2D4A4-LCD
Range 2
5
0 to 2000 ppm CO2 range
0 to 5000 ppm CO2 range
Conguration D Duct
CO2 Output 4 4 to 20 mA / 0 to (5 or 10) VDC
Temperature
Output
0
A
B
C
D
E
F
None
10 KΩ NTC thermistor type III
10 KΩ NTC thermistor type II
3 KΩ NTC thermistor
Pt100 Ω RTD
Pt1000 Ω RTD
20 KΩ NTC thermistor
RH Output 4 4 to 20 mA / 0 to (5 or 10) VDC
Options RLY Relay
Temperature Resistance Curves (in Ohms)
°C °F A B C D E F
-55
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
-67.0
-58.0
-49.0
-40.0
-31.0
-22.0
-13.0
-4.0
5.0
14.0
23.0
32.0
41.0
50.0
59.0
68.0
77.0
86.0
95.0
104.0
113.0
122.0
131.0
140.0
149.0
158.0
167.0
176.0
185.0
194.0
203.0
212.0
221.0
230.0
239.0
248.0
257.0
266.0
275.0
284.0
293.0
302.0
607800.00
441200.00
323600.00
239700.00
179200.00
135200.00
102900.00
78910.00
61020.00
47540.00
37310.00
29490.00
23460.00
18780.00
15130.00
12260.00
10000.00
8194.00
6752.00
5592.00
4655.00
3893.00
3271.00
2760.00
2339.00
1990.00
1700.00
1458.00
1255.00
1084.00
939.30
816.80
712.60
623.60
547.30
481.80
425.30
376.40
334.00
297.20
265.10
237.00
963849.00
670166.00
471985.00
336479.00
242681.00
176974.00
130421.00
97081.00
72957.00
55329.00
42327.00
32650.00
25392.00
19901.00
15712.00
12493.00
10000.00
8057.00
6531.00
5326.00
4368.00
3602.00
2986.00
2488.00
2083.00
1752.00
1480.00
1255.00
1070.00
915.50
786.60
678.60
587.60
510.60
445.30
389.60
341.90
301.00
265.80
235.30
208.90
186.10
289154.70
201049.80
141595.50
100943.70
72804.30
53092.20
39126.30
29124.30
21887.10
16598.70
12698.10
9795.00
7617.60
5970.30
4713.60
3747.90
3000.00
2417.10
1959.30
1597.80
1310.40
1080.60
895.80
746.40
624.90
525.60
444.00
376.50
321.00
274.65
235.98
203.58
176.28
153.18
133.59
116.88
102.57
90.30
79.74
70.59
62.67
55.83
78.32
80.31
82.29
84.27
86.25
88.22
90.19
92.16
94.12
96.09
98.04
100.00
101.95
103.90
105.85
107.79
109.74
111.67
113.61
115.54
117.47
119.40
121.32
123.24
125.16
127.08
128.99
130.90
132.80
134.71
136.61
138.51
140.40
142.29
144.18
146.07
147.95
149.83
151.71
153.58
155.46
157.33
783.2
803.1
822.9
842.7
862.5
882.2
901.9
921.6
941.2
960.9
980.4
1000.0
1019.5
1039.0
1058.5
1077.9
1097.4
1116.7
1136.1
1155.4
1174.7
1194.0
1213.2
1232.4
1251.6
1270.8
1289.9
1309.0
1328.0
1347.1
1366.1
1385.1
1404.0
1422.9
1441.8
1460.7
1479.5
1498.3
1517.1
1535.8
1554.6
1573.3
2394000.00
1646200.00
1145800.00
806800.00
574400.00
413400.00
300400.00
220600.00
163500.00
122280.00
92240.00
70160.00
53780.00
41560.00
32340.00
25360.00
20000.00
15892.00
12704.00
10216.00
8264.00
6722.00
5498.00
4520.00
3734.00
3100.00
2586.00
2166.00
1822.60
1540.00
1306.40
1112.60
951.00
815.80
702.20
606.40
525.60
N/A
N/A
N/A
N/A
N/A
Figure 5: CDT Model Chart
Figure 7: Elevation Chart
Figure 8: Resistance vs Temperature
RESISTANCE VS TEMPERATURE TABLE
Figure 6: CDTR Model Chart
This symbol indicates waste electrical products should not be disposed
of with household waste. Please recycle where facilities exist. Check with
your Local Authority or retailer for recycling advice.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: [phone]
Fax: [phone]
dwyer-inst.com
e-mail: [email protected]