Dwyer CDSN Room Mount CO2 Transmitter

Dwyer CDSN Room Mount Carbon Dioxide Transmitter

Posted on: 03/08/2026

The Dwyer CDSN room mount carbon dioxide transmitter is an advanced indoor air quality monitoring solution engineered for modern HVAC and BMS systems. Utilizing cutting-edge NDIR technology and automatic barometric pressure adjustment, it delivers long-term precision over a 15-year sensor lifespan while helping buildings achieve LEED® green standards. Imported and officially distributed by DLK with full CO/CQ documentation.

NDIR Sensing Mechanism and Automatic Barometric Pressure Adjustment

The Dwyer CDSN unit utilizes non-dispersive infrared (NDIR) sensing technology. This optical measurement technique analyzes infrared light absorption at specific CO2 wavelengths, providing exceptional long-term stability and eliminating zero-point drift over time. The sensor element offers an operational lifespan of up to 15 years.

A major technical advantage of the CDSN Dwyer series is its integrated digital barometric pressure adjustment. Fluctuations in ambient atmospheric pressure can alter gas density and lead to measurement errors. Thanks to this automatic compensation mechanism, the device maintains its baseline accuracy of ± $\pm 40\text{ PPM} + 3\%$ of reading without requiring frequent manual recalibration. Additionally, the Automatic Baseline Correction (ABC) feature automatically restores baseline accuracy, significantly reducing overall maintenance overhead.

Real-World Applications:

Demand Control Ventilation (DCV) in Schools: Automatically adjusts outdoor airflow based on real-time occupancy to save AHU/FCU fan energy while maintaining a healthy learning environment.
Commercial Office Buildings Pursuing LEED® Certification: Provides continuous CO2 data to the BMS to maintain strict Indoor Air Quality (IAQ) metrics and earn green building credits.
Hospitals and Healthcare Facilities: Monitors air exchange rates in waiting areas and clinics to prevent exhaled gas buildup and ensure regulatory compliance.
Shopping Malls and High-Occupancy Venues: Dynamically modulates HVAC fan speeds according to variable foot traffic, eliminating unnecessary energy consumption.

Key Operational Benefits for Contractors and System Integrators

Integrating the CDSN Dwyer transmitter into engineering projects yields clear technical advantages:

Saves installation space and hardware costs by combining CO2 sensing and an optional passive temperature sensor in a single housing.
Offers versatile field-selectable output signals via DIP switches (4-20 mA, 0-5 VDC, 0-10 VDC), ensuring seamless compatibility with standard PLC and DDC controllers.
Features a standardized wall-mount base plate with screw terminals, speeding up field wiring and reducing installation labor on site.
Constructed with a durable ABS enclosure rated NEMA 1 (IP30) with an integrated security lock feature to prevent physical tampering.

Detailed Technical Specifications: Dwyer CDSN

Technical Parameter	Specification
CO2 Range	0 to 2000 PPM
CO2 Accuracy	±40 PPM + 3% of reading
Pressure Compensation	Digital automatic barometric pressure adjustment
NDIR Sensor Lifespan	15 years
Response Time	$< 120$ seconds
Passive Temp Sensor Options	Sensor A (10KΩ type 3 NTC), Sensor B (10 $10\text{ K}\Omega$ type 2 NTC), Sensor F (20 $20\text{ K}\Omega$ NTC)
Temperature Accuracy	±1°C @ 25°C
Output Signals	Field-selectable: 4-20 mA, 0-5 VDC, 0-10 VDC, 0-20 mA, 1-5 V, 2-10 V
Power Requirements	24 VAC/VDC ±20%, 50/60 Hz
Operating Temperature	32 to 122°F (0 to 50°C)
Humidity Limits	0 to 85% RH (non-condensing)
Enclosure Material	ABS housing, NEMA 1 (IP30) rated
Agency Approvals	CE

DLK is commited to:

Supplying 100% genuine products.
Providing full Certificate of Origin (CO) and Certificate of Quality (CQ) documentation.
Offering the manufacturer's warranty along with technical support throughout the entire operation and service life of the products.