Dwyer Instruments CDTR-2N4F4 | Carbon Dioxide/Temperature/Humidity | Wall Mount | Universal current/voltage output | 20 kO Thermistor Temperature Output | North American Housing
The Dwyer Instruments CDTR-2N4F4 is a wall-mounted carbon dioxide, relative humidity, and temperature transmitter designed to combine three environmental measurements in one compact device. It provides a 0-2000 PPM CO₂ range, 0-100% RH measurement, and a 20 kΩ thermistor temperature output, with universal analog outputs for integration with building management and HVAC control systems.
This model features a North American wall-mount housing and does not include an integral LCD display, making it suitable for applications where readings are monitored through a connected controller or BMS.
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Part Number: CDTR-2N4F4
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Product Overview
The Dwyer CDTR-2N4F4 is part of the Series CDTR Carbon Dioxide, Relative Humidity and Temperature Transmitters. The series is designed to reduce the number of separate sensors required in wall or duct installations by combining multiple environmental measurements in one device.
The CDTR-2N4F4 measures CO₂ from 0 to 2000 PPM and relative humidity from 0 to 100% RH, while providing temperature measurement through a 20 kΩ thermistor output. This combination makes it suitable for HVAC and indoor-air-quality applications where ventilation control depends on multiple environmental parameters.
For CO₂ measurement, the transmitter uses a single-beam dual-wavelength NDIR sensor that automatically corrects for light-source aging. The transmitter also provides digital barometric pressure adjustment and field calibration, allowing the measurement to be adjusted for installation conditions.
The Digital Intelligence Temperature Compensation Algorithm (DITCA™) is designed to eliminate measurement error caused by self-heating in wall-mounted combination devices, supporting more reliable temperature measurement.
Universal analog outputs allow both CO₂ and relative humidity signals to be configured as 4-20 mA, 0-5 VDC, or 0-10 VDC, making the transmitter compatible with a wide range of building management controllers.
The humidity and temperature sensors are replaceable, while a physical hardware lockout helps protect configuration settings. Since the CDTR-2N4F4 has no integral LCD, a service display tool can be used for setup and calibration.
For users requiring a local display, the CDTR-2N4F4-LCD provides the same general transmitter configuration with an integral LCD.
Key Benefits
- Measures CO₂, relative humidity, and temperature in one device
- 0-2000 PPM CO₂ range
- 0-100% RH measurement range
- 20 kΩ thermistor temperature output
- Single-beam dual-wavelength NDIR sensor
- Digital barometric pressure adjustment
- Field-calibration capability
- DITCA™ temperature compensation for wall-mounted combination devices
- Universal 4-20 mA, 0-5 VDC, or 0-10 VDC outputs for CO₂ and RH
- Replaceable humidity and temperature sensors
- Physical hardware lockout for configuration protection
- Compact North American wall-mount housing
- No integral display; service display tool available for setup and calibration
- Genuine Dwyer Instruments stock with free UAE-wide shipping
Who This Product Is Best For
The Dwyer CDTR-2N4F4 is suited for:
- Demand-controlled ventilation systems
- Schools, offices, hospitals, and other indoor spaces
- HVAC monitoring and control applications
- Building management system (BMS) projects
- LEED-driven ventilation monitoring
- Projects requiring CO₂, humidity, and temperature measurements from one device
- Retrofit applications where multiple wall-mounted sensors need to be consolidated
How to Specify & Commission It
- Mount the CDTR-2N4F4 on the wall according to the installation requirements for the North American housing.
- Connect the power supply and required output wiring.
- Select the appropriate 4-20 mA, 0-5 VDC, or 0-10 VDC output configuration for CO₂ and RH.
- Set the appropriate barometric pressure value and perform field calibration if required.
- Use the service display tool for setup or calibration when necessary.
- Verify the CO₂, relative humidity, and temperature readings at the connected controller or BMS.
The transmitter operates from 16-35 VDC or 19-28 VAC and has an average power consumption of approximately 2 W, with peak consumption of 3.75 W.
Frequently Asked Questions
What does the Dwyer CDTR-2N4F4 measure?
The CDTR-2N4F4 measures CO₂ from 0-2000 PPM, relative humidity from 0-100% RH, and temperature through a 20 kΩ thermistor output.
What sensor technology does it use for CO₂ measurement?
It uses a single-beam dual-wavelength NDIR sensor that automatically corrects the CO₂ measurement for light-source aging.
What outputs are available?
The transmitter provides universal 4-20 mA, 0-5 VDC, or 0-10 VDC outputs for CO₂ and relative humidity.
How accurate is the CDTR-2N4F4?
The stated accuracy is ±40 PPM + 3% of reading for CO₂ and ±2% for relative humidity.
What temperature output does it provide?
Temperature is provided through a 20 kΩ thermistor output. The specified operating temperature range is 32 to 122°F (0 to 50°C).
Does the CDTR-2N4F4 have an LCD display?
No. The CDTR-2N4F4 does not have an integral display. A service display tool is available for setup and calibration.
Can the humidity and temperature sensors be replaced?
Yes. The humidity and temperature sensors are replaceable.
Does the transmitter require recalibration?
For buildings occupied 24 hours a day, Dwyer recommends verifying calibration every 6 to 12 months, depending on the application.
What is the difference between the CDTR-2N4F4 and CDTR-2N4F4-LCD?
The CDTR-2N4F4 has no integral LCD, while the CDTR-2N4F4-LCD includes a configurable integral LCD display.
Is genuine stock available with UAE shipping?
Yes. Genuine Dwyer Instruments stock with free UAE-wide shipping is available. Call +971 6 5436933 for pricing and current availability.
Request a Quote Today
For pricing, availability, or technical assistance with the Dwyer CDTR-2N4F4 CO₂/RH/Temperature Transmitter, contact General Tech Services LLC.
Call: +971 6 5436933
Website: www.generaltechshop.ae
