CO2 Measuring Device: Review & Recommendations

Welcome to our big CO2 measuring device test 2020, where we present you all CO2 measuring devices we have tested in detail. We have put together detailed background information and also added a summary of the customer reviews on the web.

We want to make your purchase decision easier and help you to find the best CO2 measuring device for you.

You can also find answers to frequently asked questions in our guide. If available, we also offer you interesting test videos. On this page you will also find some important information that you should pay attention to if you want to buy a CO2 measuring device.

The most important facts in brief

  • Carbon dioxide is a harmful, colourless and odourless gas which is produced, among other things, by the combustion of carbon-containing substances. High concentrations can have a toxic effect.
  • CO2 warning devices alert you as soon as the CO2 concentration in the room exceeds a certain critical level that could be harmful to you.
  • CO2 warning alarms usually only detect carbon dioxide. There are special gas detectors for gases such as butane, propane or methane and separate CO detectors for the gas carbon monoxide.

CO2 meter test: Editors’ favourites

  • The best super-small CO2 measuring device
  • The best CO2 measuring device with adjustable alarm tone
  • The best CO2 measuring device controllable via an app

The best super-small CO2 measuring device

The Air CO2ontrol Mini from TFA Dostmann is a simple, very compact CO2 measuring instrument with a readable display. The device is mobile, delivers exact CO2 and temperature readings and is well suited for living areas.

For the power supply the device should be permanently connected to a power source, but an at least short-term supply via a power bank is possible.

The CO2 measuring device is supplied with power via a USB connection. This gives you the possibility to supply the device with power via a PC or with an adapter via the power outlet.

The best CO2 measuring device with adjustable alarm tone

The Air CO2ontrol Life from TFA Dostmann is a stylish, relatively compact CO2 measuring device

The device provides exact measured values of CO2 concentration, temperature and humidity and is well suited for living areas.

The Air CO2ontrol Life by TFA Dostmann weighs 188 g with dimensions of 138 x 29 x 100 mm. Power is supplied via USB or mains adapter and the CO2 measuring device can be operated over a range of 0 to 50 °C.

The best CO2 measuring device controllable via an app

The Netatmo weather station for monitoring the indoor climate has a modern design and can be easily integrated into the home network. It provides clear information about CO2 value, temperature, humidity, air pressure, volume and weather via the smartphone. All measuring ranges are more than sufficient and the device can be extended with various outdoor and indoor modules.

The device must be permanently supplied with power via a USB cable or power supply unit. This is due to the relatively high power consumption of the sensors. A rechargeable battery would be conceivable here, depending on power consumption. The weather station is therefore less suitable as a mobile measuring device, but is also designed for a fixed location in the living room.

Guide: Questions you should consider before buying a CO2 meter

What is carbon dioxide anyway?

Carbon dioxide is a colourless, odourless and tasteless gas which can be toxic in high concentrations. Carbon dioxide is a natural component of the air we breathe and the global carbon cycle.
In technical terminology, CO2 is referred to as carbon dioxide. It is a chemical compound of carbon and oxygen. The gas is colourless, odourless and tasteless and can cause physical damage in high concentrations over a period of time.

Did you know that winemakers used to control the CO2 concentration with a candle?
Alcoholic fermentation produces carbon dioxide as a by-product. If this is in large quantities in the air, the winemaker can suffocate. That is why a candle was taken into the wine cellar. If it went out, he could be sure that there was too little oxygen and too much carbon dioxide in the air.

Carbon dioxide reacts with water to form the reaction product H2CO3, better known as carbonic acid.

As a natural component of the air we breathe, it is also an important part of the global carbon cycle. Carbon dioxide is produced by the combustion of carbon-containing substances under sufficient oxygen supply and by the cellular respiration of living organisms. This CO2 is then converted into biomass and oxygen by plants, algae and certain bacteria.

The particle concentration or the proportion of carbon dioxide is indicated by the English expression ppm (parts per million). In English: The millionth part, just as a percentage is the hundredth part of something. 500 ppm thus corresponds to a concentration of 0.05 % of the room air.

For more detailed information it is worth taking a look at the corresponding entry in Wikipedia.

Symptoms and consequences of high carbon dioxide pollution

Inhaling a high concentration of CO2 over a long period of time can lead to unconsciousness or death.
Up to 800 ppm the indoor air quality is considered good and only from 1400 ppm is it considered low.

Philipp ArnoldC02 Annex Advisor
Not only for humans can a too high CO2 value be harmful, also animals can suffer damage or die if they are exposed to a high CO2 value for too long. Therefore, checking the carbon dioxide level in the water of an aquarium is just as important. CO2 in water is not easy to measure, so instead water hardness and pH are measured and put in relation to each other. There are corresponding tables or CO2 calculators that can be used to indicate the range in which the CO2 content is found.

The maximum CO2 concentration to which a person at work should be exposed over an 8-hour day is 5,000 ppm. Above a concentration of 1.5 % (15,000 ppm), the proportion of air breathed in per minute decreases by 40 %.

From a 5% CO2 concentration (50,000 ppm) headaches and dizziness occur. If the concentration continues to rise, the heartbeat accelerates, blood pressure rises, followed by shortness of breath and unconsciousness. This is what happens during the so-called carbon dioxide anaesthesia.

Carbon dioxide concentrations above 8% (80,000 ppm) lead to death within 30 to 60 minutes.

CO2 concentrations of this magnitude occur relatively rarely. But inhaling low concentrations over a longer period of time is also harmful. Over time, the blood is enriched with CO2, which means that the oxygen supply via the bloodstream no longer functions properly. A so-called hypercapnia can be the result. If not treated in time, it can lead to damage to the brain and heart, up to and including CO2 anaesthesia with subsequent death from respiratory arrest.

What does a CO2 measuring device cost?

Depending on whether you need a simple measuring device for home use or a professional device, you will have to reckon with a price of around one hundred euros up to the four-digit range.
We will now simply assume that you do not need a special device for the detection of carbon dioxide in food packaging sealed in a protective atmosphere or similar.
We focus on CO2 measuring devices for domestic use. Since CO2 meters usually also measure room temperature and/or humidity, they are often referred to as multifunction devices.
These range in size from about 50 to about 170 Euro. Of course, the quality and the supported functions are always decisive. Very inexpensive products are also available from about 15 Euro.

Where can you buy a CO2 meter?

Of course on the Internet on the well-known buyer portals and dealer sites for measurement technology. In addition, some DIY stores and dealers for measuring technology carry CO2 measuring devices in their branches.
The first place to go if you want to buy a CO2 measuring device is of course the internet and the well-known buyer portals. In addition, dealer sites for measuring technology offer a relatively wide range of CO2 measuring devices and multifunctional devices. These sites usually also offer further information and downloads for the respective products. Furthermore, special devices can be purchased here.
It can also be worthwhile to visit a branch of a supplier of measuring technology or a DIY store. Here you can get competent personal advice if you have questions about CO2 detectors.
Here is a small selection:


Purchase criteria: You can use these factors to compare and evaluate CO2 measuring devices

The following article introduces you to the factors you can use to compare and evaluate carbon dioxide meters. This should help you decide whether a particular device is suitable for you or not.

In summary:

  • Product weight
  • Product dimensions
  • Operating temperature
  • Power supply
  • Display type
  • Display and measuring range
  • Alarm

In the following paragraphs you can read what the individual criteria are and how you can classify them.

Product weight

This criterion is particularly relevant for mobile CO2 warning devices. The lighter a warning device is, the more handy and practical it is when used flexibly.

This criterion is not only important for mobile CO2 gas measuring devices. Many models are designed to monitor the CO2 concentration from a fixed place in the home. Nevertheless, lighter models are also suitable for being taken on holiday, for example.

Product dimensions

The “size” of the measuring station is not only important for mobile devices. The larger a CO2 measuring device is, the more it attracts attention.

The CO2 gas meter should be clearly visible and the display should be large enough and easy to read. However, it should not attract attention due to its size and should be relatively discreet.

With today’s technical progress, you can orient yourself by the following guiding principle:

As small as possible but as large as necessary.

Operating temperature

Most models are designed for the living area. Nevertheless, it is advisable to observe the operating temperature range, should it become very cold/warm in rooms.

In cellars without heating it can get quite cold in winter. Similarly, smaller rooms can heat up considerably if they are exposed to strong sunlight during the day in summer.

This can lead to the CO2 sensor not functioning properly and displaying incorrect values or even triggering false alarms. In this case, make sure that the operating temperature range is wide.

Power supply

Many models are supplied with power via USB/power plug. With battery operation there is the disadvantage of avoidable battery waste.

Many of the models are powered via a USB cable or USB power supply. Although these must be permanently connected to a power source (PC or power outlet), they avoid otherwise resulting battery waste.

For battery-powered models, a battery level indicator usually informs you of low battery power.

Display type

In addition to LCD displays, there is the option of displaying via LEDs or even via an app on your smartphone.

Most carbon dioxide meters give you information about the measured values via an LCD display. This is relatively convenient, as the desired value can be called up directly from the meter at any time.

On some models, air quality readings can be viewed via an app that connects wirelessly to your smartphone. The approximate display on the CO2 meter itself is more for orientation.

Display and measuring range

In addition to the CO2 concentration, many devices also measure room temperature and humidity via the IR sensor. Measuring the volume in the interior and displaying the time and date are also useful additional functions.

Due to the nature of the IR sensor, room temperature and indoor humidity can easily be measured in addition to the CO2 concentration. These quantities should be covered by an indoor quality measuring instrument.

Allround devices also display the time and date, which can make an additional clock in the room unnecessary.


Most CO2 measuring devices use visual and acoustic signals to alert you of a critical concentration of carbon dioxide in the room air.

There are various visual solutions in addition to an acoustic alarm.

A traffic light LED display shows you in which range the CO2 concentration is approximately. If your measuring device is equipped with a display, an increased ppm value is signalled via this. Some models then ask you to air the room.

Carbon dioxide meters with wireless network connection (WLAN) even send a message to your smartphone.

Trivia: Worth knowing facts about the CO2 measuring device

How does a CO2 detector work?

An infrared sensor measures the infrared radiation emitted by carbon dioxide.

Carbon dioxide and other gases consist of two or more different atoms. These molecules absorb infrared radiation (IR) in a characteristic and unique way. This can be detected with IR devices. Water vapor, methane, carbon dioxide and carbon monoxide are gases that can be measured with an IR sensor.

IR measurement is the common technology for CO2 detection. IR sensors have many advantages over chemical sensors. They are stable and highly selective towards the measured gas. They also have a long life span. Since the measured gas does not interact directly with the sensor, IR sensors are resistant to moisture, dust, dirt, etc.

Did you know how much CO2 a car emits per 500km or how much CO2 is released when transporting strawberries?
A car emits 96.000g over a distance of 500km and 1kg of strawberries flown in from South Africa still produce 11.600g CO2. But also many activities where no means of transport is involved release CO2. For example, you produce carbon dioxide even when using an electric toothbrush or a three-minute hot shower.

What does it mean to calibrate the CO2 measuring instrument?

CO2 sensors are usually calibrated ex works to a certain carbon dioxide concentration. After some time, the accuracy of the IR sensor can decrease and it must be recalibrated.

Usually IR sensors in CO2 measuring devices are calibrated to a standard of 400 ppm. Instructions for use often state that the device should be recalibrated after a certain time.

In some cases you can do it yourself. However, the CO2 concentration of the environment must be known, otherwise the CO2 sensor is calibrated to an unknown quantity and then gives wrong values.

Or you can go to a professional. They can calibrate your IR sensor in a controlled environment to the exact value you want. You can find some offers for this on the Internet.

Can I also lend / rent CO2 measuring equipment?

Yes, in addition to various websites, you can also inquire at local hardware stores or at a specialist dealer for measurement technology.

On the Internet you can find various providers who offer the rental of all kinds of measuring instruments. Carbon dioxide detectors are also on offer.

Here is a small selection:


But you can also inquire at DIY stores in your area or at specialist dealers for measurement technology.