Which statement best describes the difference between a weir and a flume for measuring flow?

• A. A weir measures flow by water height over a notched edge; a flume uses a calibrated constriction to create a measurable velocity/pressure change.
• B. A flume measures flow by water height over a notched edge; a weir uses a calibrated constriction.
• C. A weir uses a calibrated constriction to measure pressure; a flume measures height.
• D. A weir and flume both measure flow identically.

Answer: (A)