What does the acronym NTU stand for in water quality measurement?

The acronym NTU stands for Nephelometric Turbidity Unit, which is a standard unit of measure for turbidity in water. Turbidity refers to the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye. The NTU measurement is specifically obtained using a nephelometer, an instrument that assesses the amount of light scattered at a specific angle as light passes through a water sample.

This property is crucial for water quality analysis since high turbidity can indicate the presence of harmful pathogens, sediments, or pollutants. Understanding turbidity levels in water is essential for ensuring compliance with health standards and providing safe drinking water.