Which method measures turbidity by blocking transmitted light?

Which method measures turbidity by blocking transmitted light?

• A. Turbidimetry
• B. Nephelometry
• C. Fluorimetry
• D. Absorbance spectroscopy

Answer: (A)

Light passing through a suspension is reduced when turbidity is present because particles scatter and absorb some of the light. Turbidimetry directly measures this reduction in transmitted light: as turbidity rises, more light is blocked and the detector reads a lower transmitted intensity. This contrasts with nephelometry, which samples light that is scattered at an angle (not along the original path); fluorimetry, which detects fluorescence emitted by excited substances rather than transmitted light; and absorbance spectroscopy, which assesses light absorbed by dissolved substances along the path. So the method that measures turbidity by blocking transmitted light is turbidimetry.

Light passing through a suspension is reduced when turbidity is present because particles scatter and absorb some of the light. Turbidimetry directly measures this reduction in transmitted light: as turbidity rises, more light is blocked and the detector reads a lower transmitted intensity. This contrasts with nephelometry, which samples light that is scattered at an angle (not along the original path); fluorimetry, which detects fluorescence emitted by excited substances rather than transmitted light; and absorbance spectroscopy, which assesses light absorbed by dissolved substances along the path. So the method that measures turbidity by blocking transmitted light is turbidimetry.