Formazin NTU standards are used to calibrate turbidity meters to ensure what?

• A. pH stability.
• B. Accuracy and linearity across the instrument’s range.
• C. Color correction.
• D. Temperature compensation.

Answer: (B)

Formazin NTU standards provide precisely defined turbidity values used to set a turbidity meter’s response. By calibrating with these standards, you align the instrument’s zero and slope so that readings match known NTU values across the full measurement range. This ensures accuracy (the readings reflect true turbidity) and linearity (the response stays proportional from low to high turbidity). They aren’t used to adjust pH, color correction, or temperature compensation, and while temperature can influence measurements, calibration with Formazin specifically targets the instrument’s accuracy across its range.