Drifting Velocity Sensor

Drifting Velocity Sensor

29. Drifting Velocity SensorThis scattergraph displays data from a flow monitor with a drifting velocity sensor.  Note that the reported flow velocity drifts over a wide range without a corresponding…

Drifting Depth Sensor

Drifting Depth Sensor

28. Drifting Depth SensorMost flow monitoring data can be described by the Manning Equation using either the Design Method, the Lanfear-Coll Method, or the Stevens-Schutzbach Method.  Data that do not…

Undular Jump

Undular Jump

27. Undular JumpA hydraulic jump or other transcritical flow condition may reduce the accuracy of a flow monitor.  However, this effect is not strictly limited to critical flow (Fr =…

Hydraulic Jump

Hydraulic Jump

26. Hydraulic JumpThis scattergraph is from a site that experiences a hydraulic jump.  This condition occurs when flow transitions from supercritical to subcritical flow.  In this example, the hydraulic jump…

Iso-Froude Lines

Iso-Froude Lines

25. Iso-Froude LinesThe Froude Number (Fr) is a dimensionless number used to describe flow conditions and is analogous to the Mach Number defining supersonic flight.  If the Froude Number is…

Sewer Amusement

Sewer Amusement

24. Sewer AmusementThese data are from a flow monitor installed on one of three interceptors arriving at a wastewater treatment plant (WWTP).  This unusual and entertaining pattern was created during…