Corny level monitoring

[emjay]

I remember seeing somebody with a keezer that displayed, using lights, the approximate amount of beer left I'm each keg.

Now, I can see how this might be done using float switches (at, say, every 20% height increment), but not only would that require a LOT of switches, but it seems like having all that stuff inside a keg would be pretty unsanitary.

So I'm wondering if anybody knows how this might be done in a simpler, more sanitary manner than 4-5+ level switches in every keg. And if you've done something like this, I'd especially appreciate any insight you might have.

 

[jpietraski]

Great idea. I thought about using bathroom scales. However, they aren't viewable from the outside.

 

[kerber]

I'm going to be using:

• Flexiforce Pressure Sensor
• Arduino

Each keg is going to be on a platform that will concentrate it's weight onto just the force sensor. After calibration, it should give me a pretty good idea of how much is in each keg.

I'm still up in the air as to how I'm going to display the data, though.

 

[acefaser]

I'm going to be using:

• Flexiforce Pressure Sensor
• Arduino

Each keg is going to be on a platform that will concentrate it's weight onto just the force sensor. After calibration, it should give me a pretty good idea of how much is in each keg.

I'm still up in the air as to how I'm going to display the data, though.

That would be easy with the Arduino. Just get a LED screen and have it display each sensor. You could know exactly how much beer is in each keg by knowing the full vs empty weight. Have it display percent left in each keg.
I might have to incorporate this into my keezer.

 

[kerber]

That would be easy with the Arduino. Just get a LED screen and have it display each sensor. You could know exactly how much beer is in each keg by knowing the full vs empty weight. Have it display percent left in each keg.
I might have to incorporate this into my keezer.

Exactly. I'm not sure if I'm going to use an LED bar graph, rgb LED, LED digit display, or full LCD. Either way, it should work perfectly.

 

[MoronBrothersBrewery]

Super easy and cheap!
SmartStrip Beer Volume and Temperature Monitor

 

[kerber]

Super easy and cheap!
SmartStrip Beer Volume and Temperature Monitor

That isn't nearly over-engineered enough for my liking!

 

[Hopenstein]

I always lift mine and can tell about how much is left.

 

[Bsquared]

This is a great idea! and should be fairly easy to get done.

I've been kicking around an Idea to do some thing like this since I read this about the tweeting kegerator. But I have know where the skill to know how to do it, or where to start from.

This would be really helpful too for filling corny kegs too. When I'm filling from a ten gallon batch that was fermented in a sanky keg it would be nice to be able to do it with the lid on the corny and just vent off the gas line. As of now I have to keep the lid cracked open and look in side with a flashlight. I'd be nice if there was a led display to show when the kegs full.

Please post what you find out.

 

[cdubbaya]

I'm going to be using:

• Flexiforce Pressure Sensor
• Arduino

Each keg is going to be on a platform that will concentrate it's weight onto just the force sensor. After calibration, it should give me a pretty good idea of how much is in each keg.

I'm still up in the air as to how I'm going to display the data, though.

And when you're done with that, you come come to the Twin Cities and build one for me!

PS. I'm a NDSU alum - Go Bison!

 

[kerber]

I'm still finishing my kegerator build, but once I'm done I will thoroughly document the addition of all monitoring equipment.

 

[Bokonon]

This would be really helpful too for filling corny kegs too. When I'm filling from a ten gallon batch that was fermented in a sanky keg it would be nice to be able to do it with the lid on the corny and just vent off the gas line. As of now I have to keep the lid cracked open and look in side with a flashlight. I'd be nice if there was a led display to show when the kegs full.

When I fill kegs I put them on a scale and zero it out. Same principles but less technology.

 

[thughes]

One could always use what the older recreational vehicles used: several sensors (pictured below) installed in each keg (easy to do, these thing are self-expanding rubber plugs about 1/4-3/8" diameter and cost a buck or two each) and hooked to a level gauge (diagram below) which could be installed in the front panel of the kegerator.

Me? I just keep several kegs full and ready to go, when one of them makes that sad "pppsssshhhhh" sound, I just plug another one in and then go make more beer.

 

[Bsquared]

When I fill kegs I put them on a scale and zero it out. Same principles but less technology.

Good point, how big of a scale is it? 5 gallons of beer weighs about 48lb? I just have a small digital scale for hops, I don't think It could handle that much weight.

 

[hot_carl]

I have digital fish scale I picked up for like $12 at the sporting goods store, I weigh the keg once filled, and know the empty weights. Doing some simple math will get you the rest. Now if you really want to geek out your kegerator check this out:
Tweeting Kegerator - SparkFun Electronics

They have it set up to tweet the keg level every time someone draws a beer...

 

[stratslinger]

Super easy and cheap!
SmartStrip Beer Volume and Temperature Monitor

Do those even work though? It's my understanding that they work based off of temperature differential, assuming that the side of the keg will be colder where the beer is in contact with the keg than where it is not. But, assuming your kegs are in a kegerator/keezer, their entire surface should be at the temperature your kegerator/keezer is set for, right?

Those strips basically seem a little too good to be true...

 

[kerber]

I have digital fish scale I picked up for like $12 at the sporting goods store, I weigh the keg once filled, and know the empty weights. Doing some simple math will get you the rest. Now if you really want to geek out your kegerator check this out:
Tweeting Kegerator - SparkFun Electronics

They have it set up to tweet the keg level every time someone draws a beer...

That's much like what I'll have set up with mine, though I'll be doing it per-keg. As long as I have the brainpower there, I'm going to have the arduino handle my temperature control and logging as well.

 

[gromitdj]

Do those even work though? It's my understanding that they work based off of temperature differential, assuming that the side of the keg will be colder where the beer is in contact with the keg than where it is not. But, assuming your kegs are in a kegerator/keezer, their entire surface should be at the temperature your kegerator/keezer is set for, right?

Those strips basically seem a little too good to be true...

The directions show that you have to spray the strip with warm water to reactivate the strip. I'm assuming that the portion with beer behind it will change color faster to show the level. I'm sure they work, but it seems like a lot of effort.

 

[emjay]

One could always use what the older recreational vehicles used: several sensors (pictured below) installed in each keg (easy to do, these thing are self-expanding rubber plugs about 1/4-3/8" diameter and cost a buck or two each) and hooked to a level gauge (diagram below) which could be installed in the front panel of the kegerator.

Me? I just keep several kegs full and ready to go, when one of them makes that sad "pppsssshhhhh" sound, I just plug another one in and then go make more beer.

Yeah, I was originally thinking of something similar, with the same LED arrangement.

But I think I like the weight/pressure sensors better, since they work entirely from outside the keg. With recreational vehicles, sanitation isn't really a concern, but with beer it's a different story, of course.

Only problem is that I know how to wire in level switches/sensors to activate lights, because they are either on or off. I'm thinking using a pressure/weight sensor will be significantly more complicated.

 

[emjay]

The directions show that you have to spray the strip with warm water to reactivate the strip. I'm assuming that the portion with beer behind it will change color faster to show the level. I'm sure they work, but it seems like a lot of effort.

I'm mostly looking for a nice, aesthetic display on the outside of the keezer, so the smartstrips wouldn't have ever been a consideration for me.

 

[kerber]

Only problem is that I know how to wire in level switches/sensors to activate lights, because they are either on or off. I'm thinking using a pressure/weight sensor will be significantly more complicated.

If you want to put the project off a while, I'll be doing a writeup with mine. I will be running the sensors as inputs to an Arduino dev board, which will then control the display. That being said, this could be a great project to get familiar with microcontroller development, if you don't mind the research.

 

[emjay]

If you want to put the project off a while, I'll be doing a writeup with mine. I will be running the sensors as inputs to an Arduino dev board, which will then control the display. That being said, this could be a great project to get familiar with microcontroller development, if you don't mind the research.

I've never used any sort of microcontroller before, so I hope they're pretty detailed

I think I'd prefer to use LEDs/light bars, rather than an actual screen, for a simpler aesthetic, but hopefully it won't be too difficult to adapt.

 

[kerber]

Check out the UberFridge post. You can connect the flexiforce sensor to the Arduino much like he connects the temperature probe. Nix the whole web server bit and look up how to control an LED bar graph.

 

[emjay]

Check out the UberFridge post. You can connect the flexiforce sensor to the Arduino much like he connects the temperature probe. Nix the whole web server bit and look up how to control an LED bar graph.

Thanks.

Web server or other networked stuff wouldn't be so bad. I'd love to get statistics such as rate of consumption by keg/recipe/style/total, and notifications for when the keg is about to kick.

 

[cobolstinks]

twitter4j is a great api for making tweets. If you want it to tweet wouldn't be too difficult.

 

[emjay]

twitter4j is a great api for making tweets. If you want it to tweet wouldn't be too difficult.

I'm sure there's a lot of possibilities with my smartphone. SMS would be ideal, but I'm not sure if that can be done for free.

This is all pre-planning for me right now, so I'm likely going to wait and see what the poster above is doing.

Although actually, I wouldn't mind an actual LCD/LED screen display if I could control temp with it too. I'm actually considering a system that lets me set each beer at a different temp inside my keezer (not a glycol pump or anything like that). With a bunch of normal temp controllers it's actually simple enough to do, but to have everything controlled and monitored from one display would be nice.

It's totally unnecessary, but if there were regulators on the market that could be controlled electronically (to top it all off), that'd make an absolutely incredible system. Heck, you could just program presets of temperature and pressure for every style.

 

[MotivationDedication]

If you want to put the project off a while, I'll be doing a writeup with mine. I will be running the sensors as inputs to an Arduino dev board, which will then control the display. That being said, this could be a great project to get familiar with microcontroller development, if you don't mind the research.

I look forward to this very much.

 

[MoronBrothersBrewery]

The directions show that you have to spray the strip with warm water to reactivate the strip. I'm assuming that the portion with beer behind it will change color faster to show the level. I'm sure they work, but it seems like a lot of effort.

Really?! If placing a strip on a keg is and then looking at it periodicaly is "a lot of work"... oh my!

 

[Tinga]

Could you just get a digital weight scale then wire the display to the outside of the keezer? Terr the weight of the corny then just have it display the weight of the beer inside?

 

[acefaser]

Was searching for some code for my latest Arduino project and found this info on Water Tank Depth Sensor here. The more I think about this the more I would like to incorporate it into my keezer. It would be easy to have it just monitor and post the data to Pachube and even send an email when the level is below a set percentage. I use to lift the kegs but found that roused the yeast and now just tap until empty and hope for the best. Hope to get this project underway in the next few weeks after I complete my 1000 other projects...

 

[gromitdj]

Really?! If placing a strip on a keg is and then looking at it periodicaly is "a lot of work"... oh my!

If you read the directions, it's more than just looking at it. In order to determine a level, you have to spray the strip down with warm water and wait for the strip to change colors to indicate fluid level. Not "a lot of work", but more effort than the impression that you just look at the strip to check your level.

 

[ClaudiusB]

I remember seeing somebody with a keezer that displayed, using lights, the approximate amount of beer left I'm each keg.

So I'm wondering if anybody knows how this might be done in a simpler, more sanitary manner than 4-5+ level switches in every keg. And if you've done something like this, I'd especially appreciate any insight you might have.

I have a level sensor inside my dispensing tanks, simple Reed switch and a float with magnets.
Needs to be connected to a display device like a lamp or controller.
Tells you the tank is almost empty, less than a gallon in my case.
The floats are sold by most float switch vendors.

Inside tank view

You can install multiple Reed's and resistors inside the tube and make the design to give increasing or deceasing resistance as tank empties with two wires, requires a controller or multimeter with conversion chart.

kerber's idea to use Flexiforce sensors is better if you require constant volume information.

Really?! If placing a strip on a keg is and then looking at it periodicaly is "a lot of work"... oh my!

Can you see the SmartStrip™ inside a full chest freezer?

Cheers,
ClaudiusB

 

[pinback]

Could you just get a digital weight scale then wire the display to the outside of the keezer? Terr the weight of the corny then just have it display the weight of the beer inside?

i like this idea with this scale

 

[Hoosierbilly]

If using a scale set for lbs like a fish scale, the number of lbs would equal the number of remaining pints right? At least close enough to it. That seems simple enough. The tricky part would be finding a scale that doesn't turn off after a few minutes, or if you have the on/off button next to the display on the fridge door you could just hit the button and have the weight/number of remaining pints show up...if you did this you would need it to save the tare weight...at least I know I wouldn't want to have to subtract the empty keg weight from what it displays, that's no fun. I'm going to start searching around for something like this

Recap: I need a scale that either doesn't turn or, or one that I can hit the on button and it saves the tare weight of the empty corny

 

[emjay]

If it doesn't turn off, you'd probably run out of batteries more often then you'd like.

Other than that, I guess it could work for some people, but, as I mentioned in the OP, it's not what I'm looking for. The ability to display it all in columns of LEDS, or on a single display, on the *exterior* of the keezer, is really important to me.

On a related note... how cool would it be to watch the display change in real-time AS YOU POUR?

 

[day_trippr]

i like this idea with this scale

I wonder how long a digital scale would survive at the bottom of a keezer considering the puddles of condensation and cycles of sub-freezing temperatures...

Cheers!

 

[ClaudiusB]

Could you just get a digital weight scale then wire the display to the outside of the keezer?

Scale with remote display is a better choice.

I have taken a few scales apart for my automatic grain dispensing and weighing system and the displays where not wired into the board.
The displays had a conductive rubber strip connecting the pcb to the display.

Cheers,
ClaudiusB

 

[bctdi]

If those strips work off of temp differential , then I don't see any advantage to getting them over just spraying the keg with hot water and looking for the condensation line. The condensation line will be level with the beer level.

 

[TheAleMaster]

Not necessarily simple, but pretty rad.

http://engineeringblog.yelp.com/2010/08/yelp-makes-beer-more-fun.html

EDIT: I'm not sure why, but HBT seems to append some things to this URL that redirects to some Yelp business page. Copy/paste the URL to get there.