Low-power non-invasive flowmeter
Low-power non-invasive flowmeter
(OP)
Does anybody know of any low-power (i.e. battery-operated) non-invasive flowmeters, suitable for measuring flow of "dirty" water (such as waste water, that may contain debris, possibly including strings etc.)? I've looked at mag meters and ultrasonic meters, but what I've found so far is way too power-hungry and/or "fragile". Meanwhile, common turbine meters and various types of positive-displacement meters are all "out" because of debris in the water that would instantly clog and/or damage the mechanism. This meter may be used in remote locations where no A-C power is available. Long battery lifetime is a must, and accuracy has to be better than differential-pressure and similar types! Typical would be a 2-inch application, with a flowrate of approximately 30 - 40 GPM. Of course price is important too, but at this point I'm open to any suggestions! (Full disclosure: I'm a design engineer for a company that makes flowmeters. I've been tasked with proposing a design for such an animal.) Thanks.





RE: Low-power non-invasive flowmeter
Getting past your choice of punctuation, I have a couple of problems with the quote. First, I find it very telling that someone charged with designing a flow meter would use the horrible term "accuracy". Since it doesn't mean anything it is really hard to use the term in a design. In measurement we use the terms "uncertainty" and "repeatability" to encompass the concepts implied by the word "accuracy". Second, I can get +/-0.5% uncertainty with excellent repeatability with a V-cone meter and a digital dP gauge. I can't imagine another technology that will be significantly better than that, certainly not with your power constraints.
Without the power constraints you could do a pair of weigh-scales, but everything else I can think of would have problems with the strings (and I'm not sure I could select a diverting valve that wouldn't also have that trouble).
David
RE: Low-power non-invasive flowmeter
Regards
StoneCold
RE: Low-power non-invasive flowmeter
Alternative devices could be coriolis, vibrating wire or three thermocouple type but I have no idea as to power usage.
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RE: Low-power non-invasive flowmeter