Name a commonly used method to measure water quality in fieldwork.

• A. Measuring wind speed
• B. Recording air temperature with a thermistor
• C. pH measurement
• D. Counting dissolved oxygen by manual titration

Answer: (C)

Measuring pH is a practical field method because the acidity or basicity of water directly affects chemical reactions, metal solubility, nutrient availability, and the health of aquatic organisms. Portable pH meters or simple test strips let you obtain a reliable reading on-site quickly, with low cost and easy operation. This makes pH a standard, quick indicator used to compare sites and track changes over time in water quality surveys.

Wind speed and air temperature are weather measurements, not direct indicators of water quality. While dissolved oxygen is an important water-quality parameter, measuring it by manual titration is more time-consuming and technically demanding than using a portable pH device, so pH remains the more commonly used field measurement.