Air Quality Meter

Both indoors and outdoors, the air can contain the components which, above a certain concentration, endanger health or impair the running of certain processes. Suitable air quality meters make it possible to detect the content of these substances in the air and to initiate appropriate countermeasures if necessary. Many air quality meters for monitoring the indoor air have an optical or acoustic alarm function or a colour-rated display. This means that room users are quickly warned when the values are too high and do not have to constantly pay attention to the changing numerical values. Air quality meters that are installed in the places where the measured value cannot be read at the measuring point transmit the measured data to the external display devices or to the computer systems.

Measurable parameters
Air quality meters differ primarily in the type and number of the measurable parameters. The measuring ranges and accuracies for the same parameter can also differ greatly between different types of devices. Commonly determined measured parameters include: Carbon dioxide, (CO2), formaldehyde (CH2O or HCHO), volatile organic compounds (TVOC) and particulate matter content. In addition, almost all air quality meters can determine temperature and humidity. Because of their direct and indirect effects on the environment and health, the values for ozone, nitrogen dioxides, sulphur dioxide, carbon monoxide, soot, lead, benzene and other air pollutants are also monitored by the authorities. For this purpose, the federal states have set up measuring stations both in the areas with high traffic density as well as in the rural regions. There, various air quality meters record the data and forward them for evaluation and documentation. Some of the measurement data can be retrieved from the websites of the responsible state offices.

The fine dust content is usually given as particle quantity in µg/m³ for the defined particle sizes. In the case of PM1 / PM2.5 / PM 10, the PM stands for Particulate Matter, i.e. fine dust, regardless of its material composition. The number in each case stands for the maximum particle size of the recorded particles. The different particle sizes have different effects on the respiratory tract. They are therefore measured separately and compared with the respective limit values. In addition to the three sizes already mentioned, there are many other gradations for the particle size.

Memory and interfaces in the air quality meter
If the values are to be recorded over longer periods of time with the air quality meter for documentation and evaluation, it is important to pay attention to the storage options. Some air quality meters store only very few values and not every model has an interface to digitally transfer the stored data. It is essential to check whether the intended evaluations are in general possible with the data stored by a particular device.

Air quality meters for recreation rooms
Many people spend a large part of the day indoors. Depending on the room's furnishings and the intensity of its use, alarming levels of CO2, formaldehyde and volatile organic compounds from solvents can be reached quickly. The risk of infection in the case of the infectious diseases that can be transmitted via the air we breathe is also much higher indoors than outdoors. Air quality meters offer the possibility to monitor the values and to ventilate in time if necessary. Air quality meters that at least determine the carbon dioxide content and the temperature and humidity of the indoor air are recommended for controlling the air quality in the living rooms, offices, classrooms and similar spaces. The carbon dioxide content can be used as a guide value for the hazardous substances from the breathing air. If the CO2 value rises above the specified guideline value, it should be lowered again by means of ventilation. This applies both to the rooms with window ventilation and to those with ventilation systems. If the CO2 value frequently rises above the accepted maximum value despite the automatically controlled mechanical room ventilation, the ventilation system should be checked and readjusted.

Air quality meters for measurements outside buildings
Considerable amounts of air pollutants are produced by traffic, heating systems, industry and agriculture, but also by natural processes. Their concentration and distribution is recorded at selected points by special air quality meters. If certain limit values, for example, for ozone, are exceeded, the population is warned. If the other measured values are repeatedly or continuously exceeded, spatially limited measures such as driving bans for certain motor vehicles can be initiated. The success of these measures should be reflected in the long-term improvement of the measured values.

Air quality meters for work and production sites
Air quality is also important in the flow of many biological, chemical and physical processes. For example, in the production, processing and storage of food, precisely defined conditions must be maintained so that the products such as yoghurt and cheese can be created and food can be stored for a long time. There are also high requirements for the purity of the ambient air in the production of electronic components, chemicals and pharmaceuticals. At these stationary workplaces, permanently installed air quality meters, which can transmit the measurement data to central stations, are usually used. Often, the current measurement data from these air quality meters can be used to take the immediate countermeasures if the values of a parameter are not within the intended range. At other workplaces, the work process may release increased levels of fine dust or even particles that are particularly hazardous to health. In these cases, mobile air quality meters can help to assess the situation at the point of release.

Air pollution is an issue of growing concern to more and more people. The presence of certain substances can cause discomfort, allergies and even worse, be a health hazard. Among different pollutants, there are carbon monoxide, hydrocarbons, nitrogen dioxide and nitrogen oxides, sulphur dioxide, ozone, as well as suspended particles PM2.5 and PM10. The authorities usually measure these parameters mainly in the areas of large agglomerations, such as cities. However, it is also possible to measure some of these concentrations or substances indoors using a weather station that detects, in addition to the ambient temperature and humidity, some additional parameters.

For example, a too high concentration of carbon dioxide influences people's well-being. The concentration of CO2 has been increasing because of the pollution and currently the average value exceeds 400 ppm outdoors, although it is obviously higher in the places with a lot of pollution. At the same time, indoors this value can increase significantly and in a short time. It is true that only a very high concentration is harmful to health. However, if a closed room with people in it is not regularly ventilated, the CO2 concentration increases, and will cause, among other things, the lack of concentration, headaches and drowsiness. The weather station with carbon dioxide measurement will indicate when a certain level has been reached and thus, the ventilation of the indoor space is required.

There are other health-damaging parameters found indoors, such as the presence of formaldehyde that can be measured by certain weather stations. Formaldehyde is a gas that is flammable at the room temperature, colourless and with a characteristic pungent smell. It is a material used in the manufacture of materials and many household products, that’s why it is often present in homes. The exposure to the levels exceeding 0.1 ppm is harmful to health, as it can cause irritation to the skin, eyes, nose and throat.

Another parameter to take into account is suspended particles. These are usually classified as PM 2.5 and PM 10. This abbreviation refers to the thickness of the particle. PM10 indicates that the particle has a diameter of 10 µm or less, and PM 2.5 has a diameter of 2.5 µm or less (1 µm [micrometer] is one thousandth of a millimeter). Particles are differentiated not only by size but also by their origin. For example, diesel vehicles emit PM 2.5 particles. PM 2.5 particles have a more harmful effect on health than PM 10, as they penetrate and settle in the lungs. They can even reach the bloodstream. In our product range we offer the weather stations, such as the PCE-RCM 12 station, that measure the concentration of these particles and other harmful substances.