Which instrument is typically used to determine the pH value of sewage accurately during laboratory or field testing?

Introduction / Context:
pH strongly influences biological activity, chemical dosing, and corrosion in sewers. Accurate measurement is required for process control and compliance reporting.

Given Data / Assumptions:

• Routine wastewater testing in a treatment plant or laboratory.
• Standard methods for pH measurement.

Concept / Approach:

pH is measured electrometrically using a potentiometric device (pH meter) with glass/reference electrodes. The meter reports hydrogen ion activity as pH. Other instruments serve different purposes: Imhoff cone measures settleable solids, turbidimeter measures turbidity, and jar tester evaluates coagulation/flocculation performance.

Step-by-Step Solution:

Verification / Alternative check:

Calibration with buffer solutions pH 4, 7, and 10 ensures accurate readings—standard practice in wastewater labs.

Why Other Options Are Wrong:

Imhoff cone, turbidimeter, and jar tester do not measure pH; they target settleability, turbidity, and coagulation studies respectively.

Common Pitfalls:

Using indicator papers for approximate pH when precision is required; neglecting temperature compensation on pH meters.

Final Answer:

Potentiometer (electronic pH meter)