Series CDT and CDTR Wall Mount Carbon Dioxide/
Temperature Transmitter
Specifications - Installation and Operating Instructions
Bulletin AQ-CDT/CDTR-W
Series CDT and CDTR Wall Mount Carbon Dioxide Temperature Transmitters
accurately monitor the CO
2
concentration and temperature in schools, office buildings,
and other indoor environments to help achieve LEED
®
certification. Additionally, the
Series CDTR also measures ambient relative humidity. 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 CO
2
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 field-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 an integral LCD display or the Model A-449 remote LCD display that can plug into
the mini-connector port on the side of the transmitter. Both the CDT and CDTR can be
configured to display temperature only, CO
2
only, or CO
2
and temperature together.
The CDTR can also display relative humidity or CO
2
and relative humidity together.
Push buttons are standard on the transmitters for access to the menu structure, but
the transmitter can be ordered without the buttons. To prevent tampering, the action of
the buttons can be locked out using an internal jumper selection. Menu items that can
be accessed include: engineering units, relay output set points, display configuration,
transmitter output scaling, ambient barometric pressure and field 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 unfiltered 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 firmware version will flash on
the display. A warm up period of 30 minutes is required for the
transmitter to adjust to the current CO
2
concentration.
Self calibration feature of the transmitter requires exposure to
normal outdoor equivalent carbon dioxide level once every thirty
days.
NOTICE
NOTICE
7/8 [22.35]
3-13/32 [86.52]
1-13/32
[50.01]
1-53/64
[46.43]
1-13/32
[35.72] 3X 3/8
[9.53]
4-31/64
[113.9]
35/64
[13.89]
4X 3/16
[4.76]
1-3/16
[30.20]
1-3/16
[30.20]
SPECIFICATIONS
Range:
CO
2
: 0 to 2000 or 0 to 5000 ppm (depending on model); RH: 0 to 100% (for
units configured with humidity output); Temperature: 32 to 122°F (0 to 50°C);
Accuracy:
±40 ppm +3% of reading; RH: ±2% (for units configured 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).
WARNING
CAUTION
CAUTION
CAUTION
®
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Phone: 219/879-8000
Fax: 219/872-9057
www.dwyer-inst.com
e-mail: [email protected]
