What does turbidimetry measure?

Turbidimetry is a technique that measures the amount of scattered light as it passes through a suspension of particles. When light is directed through such a sample, suspended particles will scatter some of that light, which can be quantified. The degree to which light is transmitted—and the extent to which it is scattered—provides information about the concentration of particles in the solution.

When less light reaches the detector due to more scattering, it indicates a higher concentration of particles, while a clearer sample would allow more light to pass through. This principle is what makes turbidimetry a valuable tool in various fields such as microbiology, for assessing bacterial concentrations, or in environmental science for evaluating water clarity.

The other options describe different concepts: measuring light absorption through a solid medium relates to spectrophotometry, concentration of dissolved gases pertains more closely to gas chromatography or gas sensing, and temperature variations involve calorimetry. Understanding these differences highlights the specific application and importance of turbidimetry in laboratory settings.