Tongdy CO2 Monitor with Relay

Tongdy CO2 Monitor with Relay
Regular price $199.00

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The Tongdy CO2 Monitor lets you simply and easily monitor and control indoor air quality. Use it to visually monitor air quality with its easy-to-read colored LEDs that quickly change from green to yellow to red as indoor air quality changes. When air quality gets too poor, its built-in relay can be used to turn on ventilation to bring in fresh, outdoor air.

  • Real-time Carbon Dioxide Level Control & Monitor
  • Six Colored LEDs to Easily Check Indoor IAQ
  • Built-in Relay to Control Ventilation

With its one-button on/off/auto ease of use and industry-standard 24V power requirements, the Tongdy CO2 Monitor with Relay is perfect for homes, offices, meeting rooms, classrooms, or anywhere monitoring and controlling indoor air quality is important for occupant's comfort.


  • Non-Dispersive Infrared (NDIR)
  • Sampling Method: Diffusion
  • Range: 0 – 2,000 ppm
  • Accuracy: ± 30 ppm ± 3 % of measured value
  • Life Expectancy: > 15 years


  • 1st green light <600ppm
  • 1st and 2nd green lights 600-800ppm
  • 1st yellow light 800-1200ppm
  • 1st and 2nd yellow lights 1200-1400ppm
  • 1st red light 1400-1600ppm
  • 1st and 2nd red lights >1600ppm

Electrical / Mechanical

  • Power Input TON-0007: 24VAC/VDC
  • Power Input TON-0007-WP: 110-220VAC 
  • Output Relay: <240VAC/30VDC 3A Switching Current
  • Output Relay Control: 800ppm to 1500ppm via jumpers
  • Additional Outputs: Use Model TON-0001
  • Housing: PC/ABS fireproof plastic; protection class: IP30
  • Maintenance Interval: No Maintenance Required
  • Dimensions: 100mm (H) × 80mm (W) × 28mm (D) or 2x4" wire box
  • Standard: CE-Approved


  • 1 year - See CO2Meter Terms and Conditions. 

Customer Reviews

Based on 2 reviews
If you think you need it then buy it.

Safety first! This thing works very well for automating exhaust to remove CO2. Very important because you can’t smell or sense CO2 to get it out of your workspace. Somewhat complex to setup but worth the safety feature.

Good for home

Keeps my house in the desired range for CO2 by running the HRV system using the relay connection. Range is adjustable.

"Easy to install, easy to set up, and easy calibration - just what I was looking for."

- Phillip Farrar
Water Plant Superintendent

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