Red, amber and green in the fight against Covid-19:
Breathing CO2 traffic light evaluates the air quality in rooms


How can an air quality traffic light help in fight against COVID-19?

Dirk Unsenos, General Manager of ISIS IC GmbH based in Wesel am Niederrhein says that “It must be quick and easy for people to use and the reading must be unmistakeable so that a clear course of action can be derived from it”.
“Our breathing CO2 traffic light is ready for use in a few seconds thanks to the integral sensor. It draws in the ambient air and then provides reliable information about the air quality.”

Red, amber and green in the fight against Covid-19
The “CO2 traffic light” manufactured by ISIS IC measures the air quality and delivers the result using the three familiar colours of traffic lights we see every day on our roads.
Green light means “Everything is OK”. Amber indicates a warning. “The air quality is close to the limit”.
Red means “Ventilate now”.

Independent research by Unsenos has revealed a basic need for a minimum of 800,000 air quality traffic lights in 40,000 schools across Germany alone.

The clever invention uses a special sensor for evaluating the air quality.

The SCD30 CO2 sensor module from SENSIRION performs this essential task (sales: GLYN). This module has already been used a million times to measure the air quality in heating, ventilation and air conditioning (HVAC) applications. The SCD30 can now be used to help assess the risk of infection in closed rooms.


When presenting the CO2 sensor, Stefan Besier, Line Manager at SENSIRION and Sensors Business Unit Manager at GLYN explained “the SENSIRION SCD30 operates according to the NDIR (Non Dispersive Infra-Red) principle”. “He uses the fact that CO2 molecules absorb infra-red radiation at a range of 4.3 µm. Other gas molecules absorb hardly any light in this wavelength. Inside the sensor there is a light source that emits infrared light. Opposite the light source there is a sensor that measures the radiation intensity in the 4.3 µm range.
A decrease in this radiation intensity is a reliable indicator that CO2 is present.”

Maintenance-free sensor boasts a lifespan of 15 years
The two-channel principle means that the sensor is designed to automatically compensate for long-term drifts and is very user-friendly with a lifespan of approx. 15 years.

Its compact size of just 35 mm x 23 mm x 7 mm allows for easy integration in various applications.
The SENSIRION SCD30 is fully calibrated and linearised.

CO2 traffic light manufacturer ISIS IC relies on the product quality of SENSIRION as well as support from distributor GLYN. “GLYN provided us with sustained support, especially during the start-up phase of our project, which was exactly what I would expect from a specialist in component distribution”, explains Dirk Unsenos, pleased about the cooperation with the distributor.

“We will soon be installing the first CO2 traffic lights at our headquarters and in our offices,” says Stefan Besier from GLYN, discussing the range of possible uses for the air quality traffic light. “Safety and prevention are paramount for us and our families.”

For further information about the CO2 traffic light, visit:

Contact distributor GLYN for the latest information on the SENSIRION SCD30 sensor.

Analog Power & Sensors

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