Segment V8.7: Water Meter

(Related to Textbook Section 8.6.2 - Volume Flow Meters)

In many cases knowledge of the volume of fluid that has passed through a pipe is of interest rather than the instantaneous flowrate. Such volume-measuring devices are called volume flow meters.

The household water meter, a nutating disk volume flow meter, contains only one moving part - a nutating circular disc. Water flowing through the chamber that houses the disc forces it to wobble (nutate). To complete "one wobble" of the disc, a known amount of fluid must pass through the meter. A counter connected to a pin on the disc measures the number of wobbles (and thus the fluid volume that has passed through the meter).