Dwyer Instruments CDT Specifications

SERIES CDT | CARBON DIOXIDE/TEMPERATURE TRANSMITTERS

®

FEATURES/BENEFITS

• Single beam dual wavelength NDIR sensor eliminates drift due to light

source aging offering long time stability, especially when used in areas
that can be occupied 24 hours a day

• Integral passive temperature outputs reduce number of devices mounted

in the space

• Integral display and relay output options to meet building requirements

• Service display tool available for models without an integral LCD - helps

save time during set-up and commissioning

APPLICATIONS

• Demand control ventilation in schools, ofce buildings, hospitals, and other indoor

environments

• LEED® certication

DESCRIPTION

The Series CDT Carbon Dioxide and Temperature Transmitters accurately monitor the
CO2 concentration and temperature in indoor environments to help achieve energy savings.
For increased sensor accuracy, a single beam dual wavelength non-dispersive infrared
(NDIR) sensor is used to automatically correct the measurement in both occupied and
unoccupied buildings against light source 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.

For applications that require visual indication, the wall mount congurations of the Series CDT
can be ordered with an integral LCD display. Push buttons are standard on all congurations
of the transmitters for access to the menu structure, but wall mount congurations can be

ordered without the buttons. To prevent tampering, the action of the buttons can be locked
out using an internal dip switch selection.

European style

wall mount

Duct mount

North American style

wall mount

SPECIFICATIONS

Sensor Single beam, dual wavelength NDIR.

Range CO

Accuracy CO

Temperature
Dependence

Non-Linearity 16 ppm.

Pressure Dependence 0.13% of reading per mm of Hg.

Response Time 2 min for 99% step change.

Duct Air Velocity Range 0-4000 FPM (20.32 m/s).

Temperature Limits 32 to 122°F (0 to 50°C).

Humidity Limits 10 to 95% RH (non-condensing).

Power Requirements 16 to 35 VDC or 19 to 28 VAC.

Power Consumption Average: 2 w; Peak: 3.75 w.

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 rated 2 A @ 30 VDC.

Weight 4.4 oz (125 g).

Enclosure Rating Duct mount: NEMA 4X (IP66) for housing only; Wall mount: IP20.

Agency Approvals CE.

2: 0 to 2000 or 0 to 5000 ppm (depending on model); Temperature: 32 to 122°F (0 to 50°C).
2: ±40 ppm ±3% of reading; Temperature: ±1°C @ 25°C.

±8 ppm/°C at 1100 ppm.

dwyer-inst.com

DWYER INSTRUMENTS, INC.

T: 219-879-8000 | F: 219-872-9057 | [e-mail]
800-872-9141

®

DIMENSIONS

[3.175]

[84.074]

1.10

3x .15
[3.87]

[1

[90.42]

2x .176

[4.47]

.573

[14.56]

.33

[8.38]

3x .37
[9.36]

.552

[14.02]

1.18
[30]

3.000

[76.20]

1.16

[29.39]

4.50

14.30]

3.65

[92.72]

[27.96]

2.80

[71.12]

North American style wall mount

1.08

[27.33]

3.56

European style wall mount

HOW TO ORDER

Use the bold characters from the chart below to construct a product code.

CDT -2 N 4

SERIES

CDT: Carbon dioxide/temperature transmitter

RANGE

-2: 0 to 2000 ppm CO

-5: 0 to 5000 ppm CO2 range

CONFIGURATION

N: North American style wall mount
E: European style wall mount
D: Duct mount

CO

2

4: 4 to 20 mA / 0 to (5 or 10) VDC

2 range

1/8˝

Ø3-5/16˝

4-25/32˝

[121.612]

4-9/32˝

[108.912]

4 -LCD

11-49/64˝
[298.956]

1-15/64˝

2-13/16˝
[71.238]

Duct mount

[31.411]

OPTIONS

-FC: Factory calibration certicate

-LCD: LCD display (wall only)

-RLY: Relay

-NBC: No buttons (wall only)

TEMPERATURE OUTPUT

0: None
4: 4 to 20 mA / 0 to (5 or 10) VDC
A: 10 KΩ NTC thermistor type III
B: 10 KΩ NTC thermistor type II
C: 3 KΩ NTC thermistor
D: Pt100 Ω RTD
E: Pt1000 Ω RTD
F: 20 KΩ NTC thermistor

ACCESSORIES

Model Description
GCK-200CO-2000CO2

A-449
A-449A

A-CDT-KIT

Important Notice: Dwyer Instruments, Inc. reserves the right to make changes to or discontinue any product or service identied in this publication without notice. Dwyer advises its customers to obtain the

latest version of the relevant information to verify, before placing any orders, that the information being relied upon is current.

Calibration gas kit includes a 99.99% nitrogen gas cylinder for calibrating the zero point and a 200 PPM CO / 2000 PPM CO
gas cylinder for calibrating the span point on Dwyer’s gas sensing transmitters
Remote LCD display allows remote indication of select Dwyer® wall mount transmitters for validation or certication purposes
Remote LCD display with buttons allows remote indication and calibration of select Dwyer® wall mount and duct mount

transmitters for validation and certication purposes

Accessory kit including terminal block and power supply

DWYER INSTRUMENTS, INC.

T: 219-879-8000 | F: 219-872-9057 | [e-mail]

dwyer-inst.com

800-872-9141

DS-CDT Rev. 5 | 3/19

2