Particulate Matter Measurement
Particulate Matter (PM) is a term used to refer to airborne solid and liquid particles in the atmosphere. PM can originate from natural sources such as dust storms, wildfires, sea salt, and volcanic emissions, or from human activities such as fuel combustion and the burning of waste. The size, type, and source of the PM play an important role in its physical and chemical characteristics, which can have significant health and environmental impacts. As such, PM is closely monitored and regulated by governments around the world.
PM is usually measured by sensors placed in outdoor and indoor locations. These sensors measure the concentration, size, and chemical composition of the particles in the air. Depending on the application, different types of sensors may be used, such as:
1. Laser-based particle counters that count and measure individual particles suspended in the air as they pass through a laser beam.
2. Tapered element oscillating microbalances, which use a heated wire to measure the mass of suspended particles in the air.
3. Light scatter using a photo diode to measure the scattering of light from particles passing through the beam.
4. Electrical mobility detectors, which measure the size of particles by measuring their mobility when exposed to a charge.
5. Optical particle counters, which measure the size of particles in real-time by passing light through a sample of air.
Once the PM concentration is measured, it can be used to measure the micrograms/cubic meter or µg/m³ index of the PM in a given area. This index is then used to compare levels of PM in different locations.
It is important to note that the measurement of PM is not limited to the outdoors. For indoor applications, PM may be further monitored due to the potential health risks associated with long-term exposure. As such, sensors are often placed in areas of the building where people live and work, such as classrooms and offices.
In addition to the sensors, particle monitors can also collect data from individual particles by using microscopes and other imaging techniques. This data can then be used to study the sources and effects of particle pollution.
Particulate matter measurement is an important topic for the study of air quality. By understanding the sources and effects of different types of particles, governments and individuals can work together to improve air quality and reduce health and environmental impacts.
