Simple Level Gauge for Cornies

[bobsbeer]

If the gauge is always showing half full I won't need to brew again. I will always have beer.

[Doingatun]

Why is every time I look in here, I see something else I never knew I needed !!!!

[bobsbeer]

Finally got my magnets and test tubes today, so set to experimenting. After a few trial and error attempts I finally managed it to track the level in a cornie. I initially got it working in a plastic tub, but my cornie and sankey kegs are ferrous despite being stainless steel. So it was back to the drawing board to overcome the magnets attraction to the wall of the keg. The answer turned out to be adding a bit of extra weight to the inside float, and hey presto it worked. I ended up using a 5mm spherical magnet on the outside and a couple of steel washers inside the float along with a couple of brass screws and a length of lead solder.

This is the finished prototype. The steel washers are placed at the top so the float sits horizontally when floating.

20160427_163131.jpg (15.7 KiB) Viewed 2351 times

Below is a short video showing the outside ball going down. It's a bit like watching paint dry, but it does go down.
(Not sure how to embed a video so you get two choices)
[youtube]yvfSDmDU4q4[/youtube]

https://youtu.be/yvfSDmDU4q4

[barneey]

And a full size keg with a lip?

[bobsbeer]

Not tried the sankey yet. All mine are full at the moment, so that is yet to come. I may need to do a bit of readjusting of the weight when it comes to the crusader as that has thicker steel. I may need to add another washer to the float so that it pulls the magnet down.

[brew_nick]

A third idea for level measurement is weighing scales. I use £8 bathroom scales and can tell within less than a pint when I'm going to run out. 1kg is about 2 pints and a corny weighs a shade over 5kg.
I like the magnets idea too.

Sent from my LG-D855 using Tapatalk

[Matt in Birdham]

I like it Bob - might have to rig up something similar, I'm terrible at estimating what's left in my kegs.
I always wondered whether it might be possible to determine the level of liquid in a keg from the sound it makes when you ping it? It would be cool if that was reliable - you could even make a mobile app that calculated the value for you. I suspect individual kegs are too variable though, and things like temp might have an impact.

[bobsbeer]

I am continuing to experiment with this. My next trial will be to put the magnet on the inside and use a steel ball bearing on the outside. That might give me more flexibility to play around with the float side and possibly use a different float. I'm thinking that a bigger magnet inside a bigger float might be better and overcome the lip of the sankey kegs. Something like this 40mm plastic christmas bauble.

[Goulders]

Why don't you buy some parcel scales? Weigh the keg full and empty. Then by interpolating the weight every so often you can work out how much beer is left?

[bobsbeer]

I have some parcel scales, but this looks like an easy way to just look at the level, especially once the kegs are in my kegerator. I just need to look every now and then.

[bobsbeer]

I have continued to experiment and improve the theory. I have now enclosed a magnet into a 40mm ball which goes inside the keg as the float. This should allow it to cross the weld seam in the sankey, but I have yet to try that. It works better than the test tube format, as it moves more freely inside the keg. Due to the increased separation between the two magnets, I have used an 8mm spherical magnet inside the ball and a 5mm one outside which works very well. The float magnet is currently wrapped in a paper towel for now to hold it roughly in the centre of the sphere. The plan is to use a bit of polystyrene, but I'll do that once my experiments are completed. I also need to seal the ball. As they are plastic, some model glue will be perfect.

Short video of it operating.

https://youtu.be/XdgXULLQAPU