Cairpol is a French sensor manufacturer, with production facility located near Paris in France, developing an innovative and highly efficient range of miniaturized micro-sensors (Cairsens) for air quality monitoring. Used alone or as integrated solutions, they provide real-time, highly reliable indicative data for air quality, ideal and cost-efficient for practical approach of fugitive emissions and many other air quality monitoring applications. With over twenty innovation awards, Cairpol sensors as well as integrated solutions are measuring pollutants all around the world. The acquisition by Environnement SA, a major manufacturer renowned in the field of environmental instrumentation, has been a great opportunity to keep on improving products quality and develop sales activities worldwide.

Company details

111 BD Robespierre - CS80004 , Poissy CEDEX 4 , 78304 France

Locations Served

Our Distributors

Business Type:
Industry Type:
Air and Climate - Air Monitoring and Testing
Market Focus:
Globally (various continents)
Year Founded:
1,000,000 - 10,000,000 €


Cairpol has developed an innovative and highly efficient range of miniaturized micro-sensors for air quality monitoring.

The highly innovative and patented technology employed  provides real-time, cost effective and practical approach for many fugitive emissions and air quality monitoring applications.

With sensitivity levels of up to 50-100 times better than current sensors on the market and providing real-time measurement data at a fraction of the cost of reference method analyzers Cairpol systems can be deployed quickly for fixed and portable measurement applications.

For applications such as personal exposure monitoring, industrial olfactory pollution / odor monitoring, indoor and outdoor air quality monitoring with stand alone or network configuration of sensors, Cairpol provides a quality of measurement and level of coverage that is now much more affordable.


The real-time monitoring of odorous gases or more classical pollutants emitted by industrial sites (wastewater treatment plants, refineries, landfills, etc.) appears nowadays as a requirement, in order to optimize the site process and operations, or communicate towards the neighborhoods and local public bodies. And it is more and more for the industrial to operate it.

While emissions can be measured directly at the source (in the stack, exhaust, etc.), ambient air measurement all around the sites provides a better accuracy and anticipate pollution episodes. This is why Cairpol developed around our Cairsens sensors a system of smart and autonomous stations: Cairnet.

With a meshing varying in thickness (from one to several tens stations) on his site, the operator can then measure the fugitive emissions from really low levels of concentration (close to human perception threshold) and thus enhance his operations and forecast the areas impacted by his emissions.

Without any maintenance nor calibration, it is a completely autonomous system energy-wised, with a user friendly and efficient interface, accessible from any internet-connected device. The follow-up can hence be done directly from the site or remotely, giving a better management flexibility.

Applications examples:

  • Alarm triggering after threshold overrun on one particular location, or for a given pollutant => leak detection, overproduction, treatment failure, etc.
  • Comparison between regular repeating events, with an accuracy of one minute => correlation between external events, etc.
  • Forecasting of fence-line emissions, to communicate towards surroundings.
  • Online and real-time monitoring of all the site in the world via one unique interface.
  • Database build-up for modelling software


Increasing air pollution levels are leading various organizations in charge of air quality monitoring to work constantly on how to improve their structures and gain the most accurate and reliable data possible. Indeed, the changes in mentality, and therefore in urbanism development for example, implies an access to the data faster and at a much more localized level.

With our sensors Cairsens, used within our solutions Cairtub or Cairnet, we thought about a viable alternative or addition to the existing reference networks, in terms of facility of use and maintenance, mobility or cost.

The reference stations used nowadays measure with an extreme accuracy in located areas, but requires a lot of energy, financial investment (to purchase and to maintain) and space. It is not easy then to move them easily, or to multiply them to cover more accurately the area.

In this case, our autonomous, light and maintenance free systems, in addition to their renowned great accuracy of measurement, are an interesting alternative solution, or a complementary measurement methods for those networks.

Applications examples:

  • Meshing upgrade on a specific district to monitor the traffic
  • Pre-study to determine the best location for a reference station
  • Modelling software calibration


Pollutants are numerous, and air quality monitoring as we know it (regulated by the authorities) is typically based on the main pollutants which can affect health or the environment. The pollutants of interest are representative of releases from the primary sources of pollution such as traffic and industry, or for indoor air quality because of the release of vapours and odours from building materials. Our sensors Cairsens can measure and monitor most of those pollutants.

Pollutants present in urban areas or industrial areas (H2S, CH4S, O3, NO2, nmVOC, CO, NH3, etc.): for any pollutant we have a Cairsens sensor which measures it.

Initially designed for oxidizing (O3 / NO2) monitoring to warn asthmatics of real-time pollution levels, Cairpol sensor range has been developed further to cover industrial applications including the measurement of sulfur compounds and H2S (typical odorous nuisances from waste water treatment plants and paper manufacturing facilities) and ammonia (characteristic odor from decomposition processes), but also CO, SO2, non methane VOCs (nmVOC), etc.

In France, air quality monitoring is mandatory and achieved by public associations dedicated to this field, the AASQA. In 2005, the World Health Organization (WHO) set guidelines for pm2.5 and pm10 particulate matter and for the following gases: ozone, nitrogen dioxide and sulfur dioxide. Many countries including the United States of America are required to measure additional parameters. For example, in the United States of America, the Clean Air Act requires EPA (Environmental Protection Agency) to set National Ambient Air Quality Standards for six common air pollutants. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. EPA calls these pollutants 'criteria' air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels.

O3/NO2 – Ozone and nitrogen dioxide

From the oxidizing gas family, ozone and nitrogen dioxide are the most common pollutants in the cities and their surroundings. They will impact the human health by irritating the bronchia, if not the eyes for ozone.

Ozone is considered a secondary pollutant, consequent to the transformation of oxygen from the solar UV on contact with nitrogen dioxide (NO2) and hydrocarbons (HC). Hence it generally appears at a certain distance from emissions areas of those latest pollutants (NO2 and HC), as the transformation requires some time.

Nitrogen dioxide is linked to traffic, or also from urban heating. Another source is the oxidation of the nitrogen monoxide emitted by the ozone itself.

Both being closely linked, we measure this two pollutants through one and only sensor, and we display only one unique value for both of them (no difference made between the two).

NO2 – Nitrogen dioxide

As detailed above, nitrogen dioxide is mainly caused by traffic and urban heating (20%), it can indeed be interesting to measure only this gas in order to monitor the impact of those actitivities directly for example.

CO – Carbon monoxide

This gas is also coming from the incomplete combustion of various combustibles (gas, fuel, coal, wood), and notably the traffic for example.

It also measured in industrial sites monitoring involving combustion in their process.

CO2 – Carbon dioxide

Naturally present in the atmosphere at around 390ppm, it is today the main indicator in indoor air quality. Indeed, a poor aeration in an inhabited building (and thus the lack of air renewal) will increase the CO2 concentration as it is what we exhale.

H2S/CH4S – Hydrogen sulfide and methylmercaptan (methanethiol)

Hydrogen sulfide (H2S) and methylmercaptan (CH4S) are both from the family of the total reduced sulfur compounds. They are easily recognizable by their strong odor (rotten egg for H2S, rotten cabbage for CH4S) which will be detectable at really low concentrations by the human nose.

They are mostly produced by industrial activities : extraction and treatment of gas/fuel, wastewater treatment plants, tanneries, paper mills, etc.

NH3 – Ammonia

Composed by nitrogen and hydrogen, this gas has a pungent odor, and can be irritating when its concentration in the air increases.

It is widely used (one of the most synthetized solvents in the world) in industry, as a refrigerant gas, to synthetize medicaments or also fertilizers. It is also one of the odorous gases produced by the decomposition of used water in wastewater treatment plants.

SO2 – Sulphur dioxide

Mostly produced by industrial acitivites, and notably thermal power stations, it is also produced by heating.

It is created by the combustion of gas, fuel, coal… and is directly linked to their concentration in sulphur.

nmVOC – Non methane volatile organic compounds

The family of volatile organic compounds is extremly wide, and contains in particular the BTEX (Benzene, Toluene, Ethylbenzene, Xylene).

Derived from the evaporation of combustible or exhaust gas, they are also produced by various industrial activities (refineries, wastewater treatment plants, etc.).

Our sensor measure all the non-methane volatile organic compounds.

CH2O / Organic solvents – Formaldehyde and other organic solvents

We find those pollutants essentially in the indoor spaces, as they are emitted by construction-related materials (paint, adhesive, mural coating, ceiling, wood, etc.). They are, with the CO2, a key indicator of indoor air quality.

PM – Particulate matter

They are microscopic particulate, as their size is 10 times smaller than the thickness of a human hair for the PM10, or the size of a bacterium for the PM2.5. Their effect on health, both on pulmonary and cardiovascular levels, have been highlighted by the WHO.

The emitting sources for such pollutants are again industrial or linked to the traffic, the heating being also a known source.