What is a common method for measuring turbidity in water?

Measuring turbidity in water is commonly achieved using a Secchi disk, which is a simple and effective tool. The Secchi disk consists of a flat, circular object that is lowered into the water until it is no longer visible. The depth at which the disk disappears provides a visual measurement of the water's turbidity; the clearer the water, the deeper the disk can go before it becomes obscured. This method is widely used because it is straightforward and provides an immediate observation of water clarity, which directly correlates with turbidity levels.

Other methods, while they may measure various water quality indicators, do not specifically target turbidity in the same way. pH testing focuses on the acidity or alkalinity of a solution, colorimetric analysis often deals with specific chemical concentrations in water rather than general cloudiness, and ultraviolet spectroscopy is generally used to assess organic and inorganic compounds in water rather than its turbidity. Thus, the Secchi disk remains the most recognized conventional approach for directly assessing the turbidity of water bodies.