What does turbidometry detect?

• A. Detects amount of light passing through suspension
• B. Bend in light when going through two medias
• C. A substance absorbs light at one wavelength and emits at another
• D. Filter detects light from the sample

Answer: (A)

Turbidometry gauges how cloudy a sample is by measuring light that passes through it. When the suspension has more particles, light is scattered more, and less of it travels straight through to the detector. So turbidometry detects the amount of light passing through the suspension, with higher turbidity giving less transmitted light. The other ideas—light bending at boundaries (refraction), light absorption followed by emission (fluorescence), or a filter simply detecting light—do not describe how turbidity is measured.