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Portable weir plates have always been a great way to stretch your research dollars.  The modular design allow you to tailor your flow measurement set-up with the need for costly custom construction.  Building upon what was already a successful product, we've…

Bubbler flow meters can be an excellent flow meter choice when measuring flows in flumes or weir boxes.  Bubbler flow meters are unaffected by wind, foam, steam, and floating solids and provide a high level of measurement accuracy.  Adapting bubbler meters for use with…

As we’ve seen before in our comparison of H-flume and Parshall flume manufacturers, not all “equal” products are just that…equal. Here we compare the construction details of Packaged Metering Manholes.  Packaged Metering Manholes take proven open…

The key to an accurate weir installation is the correctly sizing the upstream weir pool.  You can guarantee a successful weir installation every time if you follow these nine easy steps! The approach channel should be straight and of uniform cross-section for a distance of…

With Free Flow, Inc. (formerly of Gretna, NE) closing last year, Openchannelflow would like to extend a welcome to its former customers who are in need of assistance with their flow monitoring needs. Free Flow was primarily know for three product lines: Flumes (Parshall /…

Sometimes measuring discharge from lakes and ponds can be challenging…particularly when there isn’t a convenient spot to put a discharge weir or flume. One arrangement that has been used successfully is a vertical standpipe with a weir box mounted to the top. 

For many engineerings and end-users the default configuration for flume always includes a stilling well...and why not?  When they work, they work great - providing a convenient area to measure the flow in a flume.  When they don't work....well that's another…

Weir boxes are the preferred method of monitoring seeps from concrete and earthern dams.   Their ability to meaure low flows and retain sediment for future investigation make them a natural choice for the application.  The small foot print and ability to have differnt…

Rectangular weirs can be a good fit for Water Rights applications where the soil at the installation site is stony / has large rocks (making the installation of a flume difficult or expensive) or where a realtively large volume of water must be metered in a realtively narrow…

Every year at Openchannelflow we talk with several hundred consultants, researchers, contractors and end-users about their flow monitoring needs. Because we work extremely hard at answering all questions "flow” on this web site – and this blog in particular - we are…

Many people confuse a flume’s resolution with its accuracy and use the terms interchangeably.  The two, however, are distinct from each other.  A flume may have good resolution, but poor accuracy, and vice versa.

For flume and weir applications where the flow entering the device may not be as well distributed as one would like / or where the velocity profile needs adjustment, perforated baffle plates can be a good choice. Used in a series of two or more, perforated baffle plates help…