CDTHD – Indoor Air Quality Transmitter

Model :CDTHD


Duct Mount (CO2) / Temperature / Humidity Transmitter

Applications & Features:
  •  CDTH series carbon dioxide ( CO2 ) / temperature / humidity
    transmitters are designed for monitoring & controlling indoor
    air quality, temperature, and humidity in one unit
  • CDTHD is suitable for Duct mount
  •  High-performance NDIR digital sensor and circuit, ensure
    precise measurement and temperature compensation
  • Multiple optional RTD or thermistor sensors, compatible with
    a variety of control systems
  • Stable, reliable, and fast response
  •  15 years of CO2 sensor life without maintenance
  •  All electrical terminals are on the inside bottom, avoid any possible destroy to PCB
    when wiring
  •  Digital technology applied, multiple outputs optional, over-voltage and reverse polarity
    protection, high reliability, and anti-interference capability
  •  Light and state of art housing, easy installation


Additional information

Carbon dioxide (CO2 )


: NDIR sensor, with ABC algorithm (Automatic Baseline Correction)

Sampling Method

: diffusion


see models

Response time

<10s (30cc/min, low airflow)




0~2000ppm( measure range 400~2000ppm)


4~20mA, 0~10V, RS485/Modbus

T - Sensor

Digital, RTD or thermistor, see models

T- Range

0~50 ° C

T- Accuracy

typical ±0.5 °C @ 15-30 °C, see models

T - Output

4~20mA, 0~10V, RS485/Modbus or RTD/ thermister

Relative Humidity

RH - Sensor

: Digital polymer

RH - Range

: 0~100%RH

RH - Accuracy

3%RH (25°C, 20~80%RH)

RH - Hysteresis


RH - Response time

<10s (25°C, in slow air)

RH - Drift


RH - Output

4~20mA, 0~10V, RS485/Modbus

RH - Power supply


RH - Load resistance

≤500Ω (Current output),
≥2kΩ (Voltage output)


Optional LCD Display

D - Display resolution

: 1ppm, 0.1°C, 0.1%RH

D - Working environment

: 0~50°C, 0~95%RH (Non-cond.)