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Fiberglass packaged metering manholes are an innovative solution to the problem of needing to measure piped flow below grade. Packaged metering manholes factory integrate a flow element (usually a flume, but weirs and magnetic flow meters can also be integrated) directly into a…

Investigations by researchers have shown that in Sharp-Crested Weirs even very slight rounding or dulling of the square upstream edge of the weir crest has a measureable effect on discharge.

To accurate measure flow, thin-plate weirs are intended to operate under free-flow conditions with the nappe freely spilling over the weir’s crest.

There is a lot of confusion as to what materials are suitable for making a thin-plate weir from. Some installations use plywood, some stainless steel, some painted steel, and other fiberglass or aluminum.

In our series on Selecting a Primary Device we looked at: Choosing Between a Weir and a Flume and Choosing a Weir or Flume Style. In this closing article we now look at sizing a weir or flume.

In the first article of this series on Selecting a Primary Device we discussed criteria that can be used to select between a weir and a flume. Now our attention turns to selecting a particular style of weir or flume. The choice of device style is normally dictated by the three…

The selection of a primary device (weir or flume) for a particular open channel flow application typically can be broken down into three decisions: In this series of articles we will discuss each decision and the criteria that can be used to make a selection. In these…

Portland Water Bureau is the municipal water department for the city of Portland in the U.S. state of Oregon. The bureau manages a water supply that comes mainly from the Bull Run River in the foothills of the Cascade Range east of the city and secondarily from the Columbia South…

Sometimes there is a need to correct for a weir plate cut at an incorrect angle. While other times the flows of a particular site don’t match up well with the flow characteristics of the standard sizes of V-notch weirs. Regardless of the reason, there is a need to be able…

Let’s face it – we are all under pressure to save money and accomplish our jobs at a minimum of cost. In stream gauging, it is tempting to use wood (usually plywood) to make a weir from. Why not? The shape of a weir is deceptively simple - just a notch in an otherwise…

Staff ("Head" or "Level") Gauges provide a quick, visual indication of the level of water in a channel, flume, or weir. Although they should not be solely relied on when more precise level measurement devices are available, staff gauges allow operators to quickly gauge the…

Turning off the pumps is one of the last things that happen when a mine is closed. Slowly many of the open spaces of the mine begin to fill up with water. Rain starts to percolate thought the roof and walls and ground water, previously held at bay by the pumps begins to seep back…