Sensors for Monitoring Air Quality and Safety

• Air quality

Air quality has become a global issue. It has been propelled to global attention by the increasing air pollution resulting from industrialization and other human activities. It is not only a concern to the general public but also to industry. Particles and noxious gases are harmful health. In the industrial setup, high concentrations of carbon monoxide, methane or propane from combustion processes also offer a risk to both employees and the manufacturing processes within the industry. To overcome this there is a need for an efficient air quality monitoring system.

• Air quality sensors

Air purifiers may have been around for some time now but it was not until recently when high-end systems that incorporate smart sensors entered the market. Such high-end systems are able to display information via a screen and can as well adjust air purifiers to achieve optimum elimination of pollutants like gases, dust particles, hair and even tobacco. One sensor used in such system is the sharp GP2Y1010 by…… This sensor quantifies the presence of particles in the surrounding using infrared LED and phototransistor. A sample of the air whose quality is to be tested is administered through a series of holes embodied in the sensor enclosure that is located on top of IR LED.

As particles pass through the air quality sensor, they interact with the phototransistor which then establishes the concentration of impurities in the sample of air. One advantage of this sensor is the ability to generate an output that is directly proportional to the concentration of impurities in µg/m³. This goes a long way in simplifying the design of air-quality monitoring systems since impurity concentration is often expressed in the said similar concentrations.

In residential areas and commercial buildings, carbon dioxide emitted by occupants forms the biggest influence on the air quality. The ability to accurately detect the levels of carbon dioxide offers an effective means of controlling the HVAC systems hence minimizing the energy consumed by the same. Sensors like the T6613 and T6615 are used to detect carbon dioxide levels and can be used to facilitate demand-controlled ventilation. These sensors can be used to create a system that is activated when the level of carbon dioxide rises beyond a preset limit and shuts down when an acceptable level is reached. This reduces the amount of energy consumed by the ventilation system.

In industrial setups, leakages of flammable gasses like propane or methane pose a huge threat to safety hence need to be detected immediately. The parallax 605-00008 gas sensor is one sensor that can be used to detect LPG, alcohol, iso-butane, methane or hydrogen. It can also be used to detect smoke. The 605-00008 sensor can be used to set off an alarm when certain concentration levels are exceeded.

The gas and particles sensors play a very important role in air quality monitoring for both public, personal and industrial roles. They also come in handy in reducing the operating costs of the building by ensuring that ventilation only happens when necessary.