Reliable measurements of CO2 in air


Carbon dioxide, also known as CO2, is a colourless, odourless and non-flammable gas that is one of the natural components of our atmosphere. It is practically imperceptible to the human senses.
CO2 is heavier than air.

CO2 is not toxic to humans in low concentrations, but it does impede oxygen intake. A high concentration of CO2 in the air can cause headaches and eventually lead to loss of consciousness.

A concentration of eight percent (80,000 ppm) or more can cause death within 30 to 60 minutes.

Natural sources of CO2 include, for example, human exhalation and excretion through the skin.
CO2 is also used in many technical processes, during which it can escape into the air.

Here are a few examples: 

  • CO2 is the gas most widely used in the operation of dispensing systems.
  • CO2 is used as a natural coolant.
  • Large amounts of CO2 are produced during the fermentation process of alcoholic drinks.
  • CO2 is used as a protective gas in many packagings for the preservation of foods.
  • CO2 is particularly suitable for combating burning liquids and gases.
  • Dry ice pellets (CO2) are used for jet cleaning in industry and trade.


In the event of a technical error or improper application, high concentrations of CO2 can form within a short time. This can lead to life threatening situations.

CO2 is therefore an important indicator when it comes to the quality of the air.
To ensure our well-being and safety, certain limit values must not be exceeded.

The German Federal Environmental Agency has issued health reviews and recommendations for the CO2 content in the air as well as limit values that must not be exceeded in the workplace.

CO2 Measurement

Sensirion’s SCD30 is a CO2 sensor that operates in accordance with the NDIR principle. It makes use of the fact that CO2 molecules absorb infrared radiation in the 4.3 µm range. 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 sign of the presence of CO2.


The SCD30 is fully calibrated and linearised. The use of dual-channel technology automatically compensates for any long-term drift. Its compact size of just 35 mm x 23 mm x 7 mm enables easy integration in various applications.


The SCD 30 is now available ex-stock from GLYN.


Further information can be found here:


CO2 measuring range

Temperature measuring range

Relative humidity measuring range


Average power consumption

Data sheet



10,000 ppm

-40 to 120 °C

0 to 100 %

3.3 to 5.5 V

17 mA



Analog Power & Sensors

+49 6126 590-388
+49 6126 590-188

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