A good friend of mine, also a water measurement expert, does professional work with sheet metal, and he has come up with accurate, slightly lower cost cutthroat flumes for lower flows!
Okay, this may not be the most exciting of subjects, so I am including a photo of our new Springer Spaniel puppy Netti. She is 9 weeks old, 10 lbs., and is training very fast. She’ll keep the raccoons out of the landscaping and garden, and might hunt too. She is a natural at fetching tennis balls!
Back to flumes – posts here covered the EZ-Ramp flumes (3.5, 7,0, 10, and 20 cfs) several times, so what is different about the cutthroats? The name comes not from cutthroat trout, which I loved to catch in Wyoming when I was a kid. Instead, it is because the throat section is cut out of what would otherwise be a Parshall flume, while still having high accuracy. These particular cutthroats are for LOW flows, say 0.05 to 1.0 cfs with high accuracy AND still reading flow directly in cfs.
The manufacturer is working to include higher flow ranges (3 cfs and more) with very stiff but still relatively low-weight construction.
The neat thing is, the costs are a little less than the EZ-Ramp flumes, comparing the same sizes. They are shipped fully built, but the manufacturer’s location is much closer than the bigger companies in Idaho and Utah, so shipping is less, too. Who doesn’t want to save some money?
My friend is working on a couple of other types of flumes, too, including a Montana Cutthroat. Each flume has advantages and disadvantages, depending on the flow range, site, soils, geology, sediment transport, and application. What are the advantages of each type of measurement device? We have discussed weirs, flumes, and orifices in posts here, and later we’ll discuss differences in flumes. In the meantime, a website with some very good information on flumes and other measurement devices is http://openchannelflow.com/
This is a shorter post, after two of the last three being long posts. I wish you success at flow measurement, understanding and protecting your water right, and (never joyful) regulatory compliance. Have a good night!