A WEIR is the name given to concrete or masonry structure built across a river (or stream) in order to raise the level of water on the upstream side and to allow the excess water to flow over its entire length to the downstream side. Weirs may also be used for measuring the rate of flow of water in river or streams.Different shapes of WEIRS generally used are sharp-crested weir, broadcasted weir and ogee shaped weir.In the unit a centrifugal pump sucks the water from the sump tank, and discharges it to a small flow channel. The weir is fitted at the end of channel. All the weirs are interchangeable. The water-flowing over the weir falls in the collector. Water coming at from the collector can be directed to the sump or can be directed in to the measuring tank for measurement of flow.
 The unit is provided with following weirs:
(a) Sharp-crested weir.
(b) Broad-crested weir.
(c) Ogee shaped weir.
 Pump 1/2 H.P. monoblock.
 Flow measurement Measuring tank calibrated water flow meter is used.
A technical manual accompanies the unit.
 Floor surface 2.5 m x 1.5 m.
 230 v, 5 amp supply with earthing connection