Water and Wastewater Terms Beginning S

A B C D E F G H I J K L M N O P Q R S T U V W Y Z

secondary element

The secondary measuring device or flowmeter used with a primary measuring device (element) to measure the rate of liquid flow. In open channels, bubblers and floats are secondary elements. Differential pressure measuring devices are the secondary elements in pipes or pressure conduits. Secondary measuring devices measure the liquid level in open channels or the differential pressure in pipes and convert this measurement into an appropriate flow rate according to the known liquid level or differential pressure and flow rate relationship of the primary measuring device. This flow rate may be integrated (added up) to obtain a totalized volume, transmitted to a recording device, or used to pace an automatic sampler.