Which unit measures the amount of light scattered by particles suspended in a water sample?

The measurement that accurately captures the amount of light scattered by particles suspended in a water sample is expressed in Nephelometric Turbidity Units (NTU). NTU is determined by passing a beam of light through a water sample and measuring the scattered light at a specific angle from the incident light. This method is commonly used because it provides a reliable quantification of turbidity levels, which is essential for assessing water quality.

Choosing NTU as the correct unit highlights the importance of this measurement in various environmental health contexts, including drinking water safety, wastewater treatment, and ecological studies. The ability to gauge the cloudiness or turbidity of water directly correlates with the concentration of suspended particles, which can include sediments, microorganisms, and other pollutants, making it a critical factor in evaluating water quality.

Other units, such as Formazin Turbidity Units (FTU), Jackson Turbidity Units (JTU), and Lincoln Turbidity Units (LTU), may not be as widely used or may measure turbidity through different methodologies, but NTU is the most accepted standard in many scientific and regulatory contexts.