How is open channel flow measured?

The common method of measuring flow through an open channel is to measure the height or HEAD of the liquid as it passes over an obstruction (a flume or weir) in the channel. By measuring the time from transmission of an ultrasonic pulse to receipt of an echo, the water level or “Head” is accurately measured.

How discharge through open channel is measured?

The discharge may be estimated by measuring the water surface elevation just upstream of the critical section and converting it to discharge using a calibration curve, which is most often provided by the manufacturer. Parshall flumes are readily available in widths from 2 inches to 120 inches (5.08–304.8 cm).

How do I know if my flow meter is accurate?

to know the accuracy. The accuracy of a flow meter can be stated one of two ways; as a percentage of full scale (FS) or as a percentage of reading (RD, also referred to as per- centage of rate). It is important to understand the meaning of both so that your flow meter performs as expected and with the desired accuracy.

Which is a common method of open channel flow measurement?

A very common method of open-channel flow involves the use of a hydraulic structure such as a weir or flume. Measuring flow into a reservoir is a common application where open-channel flow measurement comes into play. Open-channel flow occurs when liquid flows in a conduit or channel with a free surface.

Which is the best open channel flow transmitter?

Our highly accurate devices for open-channel flow range from the SITRANS Probe LU240 compact transmitter to the MultiRanger, HydroRanger, and SITRANS LUT400 controller series. For added confidence, the HydroRanger and SITRANS LUT400 series are MCERTS-certified.

What’s the accuracy of a weir and flow meter?

Under laboratory conditions, a properly installed Weir can typically achieve accuracies of +/-2 to 5%; under most field conditions accuracies within 5 to 15% may be expected. However, the overall accuracy obtained from the flow measurement systems (the weir and flow meter) can be affected by a number of factors,…

Which is an example of an open channel?

Examples of such structures include streams, rivers, irrigation ditches, canals, partially full pipes, and water conveyance flumes. Some of the more common methods currently in use to measure open channel flows are: The complete flow stream is collected a container for a fixed length of time.