Dwyer Instruments CDTR-2D404 | Carbon Dioxide/RH/Temperature Transmitter | 2000 ppm CO2 range | Duct mount | 4 to 20 mA/0 to (5 or 10) VDC CO2 output | RH outputs & no temperature output
The Dwyer Instruments CDTR-2D404 is a duct mount carbon dioxide and relative humidity transmitter designed for indoor air quality monitoring, HVAC control and demand-controlled ventilation applications. It measures 0-2000 PPM CO₂ and 0-100% RH and provides universal 4-20 mA, 0-5 VDC or 0-10 VDC outputs for CO₂ and RH.
This model has no temperature output and features a NEMA 4X (IP66) duct housing, making it suitable for applications where CO₂ and humidity monitoring are required without a temperature signal.
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Part Number: CDTR-2D404
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Product Overview
The Dwyer CDTR-2D404 combines carbon dioxide and relative humidity measurement in a single duct-mounted transmitter, helping reduce the number of individual sensors required in HVAC and building automation systems.
The transmitter provides a 0-2000 PPM CO₂ measurement range and 0-100% RH measurement range. Unlike CDTR variants equipped with temperature outputs, the CDTR-2D404 has no temperature output, making it suitable where temperature measurement is handled separately.
A single-beam dual-wavelength NDIR sensor provides CO₂ measurement and automatically corrects for light-source aging in occupied and unoccupied buildings. The transmitter also supports digital barometric pressure adjustment and field calibration.
Dwyer's Digital Intelligence Temperature Compensation Algorithm (DITCA™) helps eliminate measurement error associated with self-heating in combination sensing devices.
Universal analog outputs for CO₂ and RH can be selected as 4-20 mA, 0-5 VDC or 0-10 VDC, allowing the CDTR-2D404 to integrate with a wide range of building management and HVAC controllers. Current outputs support a maximum 500 Ω load, while voltage outputs require a minimum 500 Ω load.
The humidity and temperature sensors are replaceable, and a physical hardware lockout helps protect configuration settings. The CDTR-2D404 has no integral display, but a service display tool is available for setup and calibration.
The transmitter features a NEMA 4X (IP66) duct housing and supports duct air velocities from 0 to 4000 FPM (20.32 m/s).
Key Benefits
- Combined CO₂ and relative humidity measurement in one duct-mounted transmitter
- 0-2000 PPM CO₂ measurement range
- 0-100% RH measurement range
- No temperature output for applications where temperature is monitored separately
- Single-beam dual-wavelength NDIR CO₂ sensor
- Automatic correction for CO₂ sensor light-source aging
- Digital barometric pressure adjustment and field calibration
- DITCA™ temperature compensation
- Universal 4-20 mA, 0-5 VDC and 0-10 VDC outputs
- Replaceable humidity and temperature sensors
- Physical hardware lockout
- NEMA 4X (IP66) duct housing
- Supports duct air velocities up to 4000 FPM (20.32 m/s)
- Suitable for demand-controlled ventilation and building automation
- Genuine Dwyer Instruments stock with free UAE-wide shipping
Who This Product Is Best For
The Dwyer CDTR-2D404 is suitable for HVAC engineers, facility managers, building automation professionals and system integrators who require CO₂ and humidity monitoring from a single duct-mounted transmitter.
It is particularly suited to applications where temperature measurement is handled by a separate sensor or controller.
Typical applications include:
- Demand-controlled ventilation in schools and offices
- Indoor air quality monitoring
- Hospitals and commercial buildings
- Building management and HVAC control systems
- CO₂ and humidity monitoring projects
- Ventilation monitoring and energy-efficiency projects
- Systems where temperature measurement is provided separately
How to Specify & Commission It
- Install the CDTR-2D404 duct mount transmitter according to the manufacturer's installation requirements.
- Connect the appropriate 16-35 VDC or 19-28 VAC power supply.
- Select the required 4-20 mA, 0-5 VDC or 0-10 VDC output configuration.
- Set the appropriate barometric pressure value.
- Perform field calibration if required using the service display tool.
- Connect the CO₂ and RH outputs to the building management or HVAC controller.
- Verify the CO₂ and RH readings before commissioning the ventilation or control system.
Frequently Asked Questions
What does the Dwyer CDTR-2D404 measure?
The CDTR-2D404 measures CO₂ from 0-2000 PPM and relative humidity from 0-100% RH. This model has no temperature output.
Does the CDTR-2D404 provide temperature measurement?
No. The CDTR-2D404 has no temperature output. It is designed for applications requiring CO₂ and RH measurement without a temperature signal.
What outputs are available?
The transmitter provides universal 4-20 mA, 0-5 VDC or 0-10 VDC outputs for CO₂ and RH.
How accurate is the CDTR-2D404?
CO₂ accuracy is ±40 ppm + 3% of reading, while relative humidity accuracy is ±2%.
What type of CO₂ sensor does it use?
It uses a single-beam, dual-wavelength NDIR sensor with automatic correction for light-source aging.
Does the CDTR-2D404 have a display?
No. There is no integral LCD. A service display tool is available for setup and calibration.
Does the CDTR-2D404 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 enclosure rating?
The duct housing is rated NEMA 4X (IP66).
What power supply does the CDTR-2D404 require?
It operates from 16-35 VDC or 19-28 VAC. Average power consumption is 2 W, with peak consumption of 3.75 W.
Is genuine stock available with UAE shipping?
Yes. Genuine Dwyer Instruments stock is available through General Tech Services LLC with free UAE-wide shipping. Call +971 6 5436933 for pricing and current availability.
Request a Quote Today
For pricing, availability or technical assistance for the Dwyer CDTR-2D404 CO₂/RH transmitter, contact General Tech Services LLC.
Call: +971 6 5436933
Website: www.generaltechshop.ae
