Flow meter tally?

[DaveB]

I buy sap from a couple of people and I've always gauged the amount of sap in a collection bin and used that as the amount that I'm collecting and paying them at the end of the season. Is there a more precise way to know how much I am collecting such as a flow meter with a sum of what was collected? I know there are ones for fuel but what about a food grade option? Any thoughts? I thought about a stick to measure the level of sap but they all have different bins so that's why I'm wondering about something more precise that measure the exact amount I'm pumping.

[FarmerKJS]

There are flow meters available, there are mixed opinions about accuracy. I don't know how you have your tanks setup, but here is something that might work. They guy that I take my sap to has a clear tube plumbed into the tank that we dump into. You can fill up the tank with a known quantity and then mark it on the tube.

[minehart gap]

Water meters are fairly accurate and available at plumbing supply houses or online. Some are stainless some brass. I would think that they would be considered food grade but not sure about it.

[DrTimPerkins]

The accuracy of any water meter is related not only to the quality of the meter, but also the quality of the installation. There are certain rules to follow, which include (but this isn't an all-inclusive list): straight run of pipe before/after the meter for at least 10X the diameter of the meter, no elbows or restrictions in the line immediately before/after the meter, correct orientation (usually liquid going UP or straight across, never down unless you always have a full-pipe), no air in pipe, etc. Then after you install....calibrate.

[Amber Gold]

How do you properly calibrate a flow meter?

I think my flow meter is overestimating flows by ~5% based on the 725 gal tank markings and the meter readings.

[DrTimPerkins]

The procedure varies depending on the meter. At the simplest, run a known volume of liquid through the meter as installed and see what you get.

[bobbyjake]

In my opinion, if you are happy with the arrangement and so are your sellers, don't mess with it too much.

Water meters are very accurate, but as Tim Perkins points out, installation configuration is key. The other element is making sure you can mount it permanently in a convenient manner so it is protected and the installation remains accurate throughout the season (ideally multiple seasons). Size would also be a consideration. 3/4" - 1" water meters are pretty inexpensive, but larger ones start to get pricey and are not designed to have fits and spurts of liquid chugging at them, like when pumps catch and loose prime. Most deliveries are going to need to be done timely and waiting 20 minutes to be able to pump off a significant volume through a smaller meter may not be convenient for your sellers.


The easiest way is to have a means of measuring the tanks bringing sap to you and a means of measuring your receiving tank and just check that the 200 gallons being delivered is the same 200 gallons that arrived in your tank. If they are within a +/- 5% of each other, it might take you years to cover the cost of the water meter installation, for nearly no gain. A reasonably level unloading area helps.

[DaveB]

I pickup sap from the sellers and I just want to make sure that we are being fair to each other. I have about 5 pickup points with 3 different types of bins but they have a known quantity and I usually just gauge how much is in the bin and to the nearest 5-10 gallons. I always measure the sugar content of the sap that I collect and this lets them know which lines are most productive. That's helped one guy know where to expand. We are both kind of "numbers" people and I was just wondering if there was a more accurate way of measuring what I'm collecting.

I'm also thinking this could be handy to know what I'm boiling each day as well. Right now I guess based on markings on my main tank and I think it would be interesting to see how many GPH I do during different parts of the day.

Thanks for the suggestions for a water meter. I was drawing a blank there and could not think of that option. I just have to see how one would work and if it keeps its accuracy (and if it's worth the hassle).