Which measurement device requires the probe to be positioned parallel to the hydrant outlet when taking a reading?

• A. Even with end of hydrant outlet
• B. Parallel to outlet opening
• C. Distance equal to diameter of outlet
• D. 1-1/4 inch from end

Answer: (B)

Positioning the probe parallel to the hydrant outlet aligns the sensing element with the main flow path, so the measurement reflects the true discharge. When the probe sits in line with the flow, the reading is stable and representative, minimizing the distortions caused by turbulence, eddies, or edge effects that occur if the probe is placed at the end, angled, or offset. This orientation reduces interference from the hydrant body and provides a consistent, accurate reading of the water exiting the outlet.