Which statement best describes the Parshall flume?

• A. It is the most common flume for flow measurement.
• B. It is rarely used due to complexity.
• C. It is used only for wastewater dosing.
• D. It cannot measure wide flow ranges.

Answer: (A)

Parshall flumes are fixed-geometry flow meters used in both open channels and partially full pipes to measure discharge. Water passing through the throat creates a predictable relationship between the head above the throat and the flow rate, which is captured by standard discharge equations. This device is favored because it has no moving parts, is durable and easy to install, and can cover a wide range of flow rates simply by selecting the appropriate throat size. That practicality and reliability are why it’s widely adopted as the default flume for flow measurement in wastewater and related applications.

The idea that it’s rarely used is not accurate—the Parshall flume’s simplicity and robustness make it a common choice. It isn’t exclusive to wastewater dosing; it’s used for general flow measurement in sewer systems and other water-flow scenarios. And because throat sizes can be chosen to match expected flow ranges, it can handle a wide range of flows, so the statement about not measuring wide ranges isn’t correct.