Description • flow over sharp-crested weirs • typical measuring weirs: Thomson weir and Rehbock weir Sharp-crested weirs are a type of control structure that dam up an open channel in a defined manner. They are often used to determine the discharge of an open channel. MR-HM 150.03 contains two different plate weirs as sharp-crested weirs. The two weirs are typical measuring weirs with defined weir openings: in the Thomson weir the opening is triangular; in the Rehbock weir it is rectangular. The weirs are installed and screwed in place into the MR-HM 150 base module. The weir can be installed and replaced quickly and easily. Water from the small experimental flume in MR-HM 150 flows over the weir being investigated. A level gauge for detecting the head is included in the delivery. The head is used to determine the discharge, which is then compared to the measured values from MR-HM 150. Learning objectives/experiments • free overfall at the sharp-crested weir • plate weirs as measuring weirs · determining the discharge coefficient · comparison of measuring weirs (Rehbock, Thomson) • determining the discharge • comparison of theoretical and measured discharge Specification [1] discharge measurement in open channels using 2 measuring weirs [2] measuring weirs for installation in the MR-HM 150 experimental flume [3] Thomson weir with V-profile [4] Rehbock weir with rectangular profile [5] level gauge with scale for determining the head [6] level gauge can be positioned anywhere along the experimental flume Technical data Weirs • material: stainless steel • self-sealing • rectangular profile · LxW of the section: 60mm • V-profile · angle of the section: 90° · height of the section: 50mm Measuring ranges • head: 0…200mm LxWxH: 230x190x8mm (weir plates) LxWxH: 290x190x290mm (level gauge) Total weight: approx. 4kg Scope of delivery 2 weir plates 1 level gauge 1 set of instructional material
