Author Topic: Measuring Spring Flow  (Read 957 times)

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Offline SLOweather

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Measuring Spring Flow
« on: January 16, 2017, 04:17:52 PM »
We have a seasonal spring on our lot. I know it's a wet season when it starts flowing. It hasn't run in years, maybe 2010.

With the large amount of rain we received in the last couple of weeks, it has started to run again. I believe it drains the serpentine outcrops across the street.

I usually use a gallon milk jug and a stopwatch to measure the flow. Friday, it took ~33 seconds to fill, Sunday, ~35 seconds (1.8 and 1.7 GPM)

I got to wondering how to instrument that. Being an old wastewater treatment guy, I thought about V Notch weirs and Parshall flumes. But building something that small and reading it accurately is a bit daunting.

Then I remembered I have an SEA YF-S201 flow sensor for the solar spa heater I have yet to build.



5-24 VDC, 5 volt square wave out, (Pulse freq in Hertz)/7.5 = flow in liters per minute, or (Pulse freq in Hertz)/1.98 should give GPM)

So, I assembled the flow sensor, a 9v battery, some clip leads, and a funnel, hose and a fitting, and a meter that reads in Hz.



As a proof of concept, it works, although it's hard to hand-hold it all and get decent readings. Entrained air screws up the meter impeller. After some more thought, I think I need to craft a proper penstock to let any air escape, level horizontal mounting for the sensor, and then a discharge line with an elevated end to ensure that the sensor always runs full.

Then, a long run of 3 conductor cable to get it back to the logger.

Or.... The 5 volt output might be a little high, but I could reduce that with a resistor divider and run it to the anemometer input of a Davis VP2 ISS...

Offline floodcaster

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Re: Measuring Spring Flow
« Reply #1 on: January 17, 2017, 03:14:51 PM »
Very cool! Nice work.

Quote
I thought about V Notch weirs and Parshall flumes.
Now you're talking my language.  :grin:
Bill


 

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