Opacity is a measure of how much light is blocked or absorbed by particulate matter in a gas stream. It is often used to monitor emissions from industrial stacks.
Sources:
- Combustion processes in power plants and industrial boilers.
- Vehicle emissions, especially from diesel engines.
- Incineration of waste materials.
Effects:
- Environmental: Reduces visibility, contributes to air pollution, and affects climate.
- Health: Particulate matter can cause respiratory and cardiovascular diseases.
Measurement:
- Opacity Meters: Use a light source and a detector to measure the amount of light absorbed by particulates in the exhaust stream.
- Transmissometers: Measure the transmission of light through a gas sample to determine opacity.