What is the primary use of a turbidity meter in water treatment?

• A. To assess the clarity of water and particle content, indicating filtration performance.
• B. To measure water temperature.
• C. To determine pH level.
• D. To count microbial colonies.

Answer: (A)

A turbidity meter quantifies water clarity by measuring how much light is scattered by particles suspended in the water. This directly reflects the amount and size of solid material present and serves as a practical indicator of how well the treatment process, especially filtration, is removing those particles. In operation, filtration performance is judged by low turbidity levels (often reported in NTU); if turbidity rises, it signals that filtration or coagulation/flocculation is not performing effectively and adjustments may be needed. Turbidity specifically concerns suspended solids rather than dissolved substances, and it does not measure temperature, pH, or microbial counts, which require different instruments or methods.