Monitor CO2 in Schools with the CDT-S Transmitters!

Series CDT-S Carbon Dioxide and Temperature Transmitter

Dwyer recently released its new -S option for the Series CDT carbon dioxide and temperature transmitters. Built upon Dwyer’s standard carbon dioxide transmitter, the -S option has a front-facing LED that illuminates when the CO2 level exceeds 1,100 PPM. 

This new feature addresses concerns raised by legislation, including California Assembly Bill 841 and Nevada Assembly Bill 257. California’s Assembly Bill 841 was signed into law in 2020, while Nevada’s Assembly Bill 257 was approved in 2021. These bills proposed several provisions governing indoor air quality in the public school system, including that each classroom will be equipped with a carbon dioxide monitor that: 

  • Is hardwired or plugged in and mounted to the wall at least 3 feet but not more than 6 feet above the floor and at least 5 feet away from any door or operable window;
  • Displays readings to appropriate personnel through a display on the monitor or through an application on an Internet website or a cellular phone;
  • Provides a visual notification when the carbon dioxide levels have exceeded 1,100 PPM; 
  • The monitor maintains a record of previous data that includes at least the maximum carbon dioxide concentration measured; 
  • The monitor has a range of 400 ppm to 2000 ppm or greater.

Studies have shown that CO2 levels affect not only concentration and ability to focus, but also overall health. Generally, concentrations of 1,000 to 1,100 PPM are accepted in occupied indoor spaces. When CO2 levels exceed this number, occupants can become drowsy, develop headaches, lose concentration, have increased heart rates, or even become nauseous. The air itself may feel stuffy, and require additional ventilation.

The CDT-S allows occupants to monitor their CO2 levels and know when their indoor air quality is not ideal. This will allow them to make adjustments to their ventilation system as needed, increasing indoor air quality.

To learn more about the Series CDT-S carbon dioxide/temperature transmitter, or any Dwyer product, please visit our website: