Once the liquid level is successfully measured, a computing device is used to translate that
level measurement into a suitable flow measurement (and in some cases even integrate that flow
measurement with respect to time to arrive at a value for total liquid volume passed through the
element, in accordance with the calculus relationship V =
R
Q dt + C).
A technique for providing a clean and “quiet” (still) liquid surface to measure the level of is
called a stilling well. This is an open-top chamber connected to the weir/flume channel by a pipe, so
the liquid level in the stilling well matches the liquid level in the channel. The following illustration
shows a stilling well connected to a weir/flume channel, with the direction of liquid flow in the