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View Full Version : Free 3/16 flow meter


littleTapper
03-09-2025, 07:17 AM
Can't believe I didn't think of this a long time ago, but whipped up a spreadsheet to help the calculation. Anyone who wants to check the math; please do!

Make two marks a foot apart on the 3/16 tubing, then time how long it takes a bubble to get from one to the other. Luckily almost everyone has a stopwatch available on their phones. Rates are gallons/min and gallons/hour.

https://www.isaacolson.com/web/maple/flowRates.png
maple flats
03-09-2025, 09:56 AM
Can't possibly be vary accurate for one reason, the length of the gas bubbles is not a constant, it will vary as temperatures and air pressure vary. it might come close but at best t's just a very rough estimate.
If you want to test the flow on any given day, time how long it takes a container of known size it takes to fill, but realize that will only give you the flow right then, it will usually vary every day, even at different times during the same day.
Just look at the flow, but be careful, it might hypnotize you.
littleTapper
03-09-2025, 11:11 AM
Oh, I'm well aware of the limitations and that things change throughout the day. But, it costs very little to do and yes, measuring what's collected will be better. It's just a tool and there can be value in knowing point in time flow rates.
ryebrye
03-12-2025, 01:28 PM
Your match checks out (or at least it matches mine). When I was doing 3/16 into jugs I did something similar so I could estimate when I'd have to go swap out collection containers.

I did a two-foot distance instead of one-foot to try to minimize my the impact being off on my timing might be.

I _think_ Tim Wilmot mentioned timing bubble speed as a way to estimate sap flow in his original paper on the 3/16 tubing systems
littleTapper
03-12-2025, 02:17 PM
Your match checks out (or at least it matches mine). When I was doing 3/16 into jugs I did something similar so I could estimate when I'd have to go swap out collection containers.

I did a two-foot distance instead of one-foot to try to minimize my the impact being off on my timing might be.

I _think_ Tim Wilmot mentioned timing bubble speed as a way to estimate sap flow in his original paper on the 3/16 tubing systems

Cool, thanks for sharing! Yes, more distance would be better. I have three lines in parallel in a spot where it's easy to read, so I just did 1' but I can do more. Probably should.