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bdh · 12-17-2012, 03:18 PM

Quote:

Originally Posted by Vesku

Do you see, there's that "Wheatstone Bridge" right there

Have anyone tried to build the 2 electrode system? I've seen some discussions about it, but they all measured capacitance rather than impedance. There was issues with heat affecting the readings. Also an AC current is needed for the measurement to avoid electrolytic corrosion.

If only a few different level indication are needed, here's a simple circuit that works: http://www.electronic-circuits-diagrams.com/alarmsimages/6.gif I didn't have LED's on mine, but send the info to the Arduino. I also had 3 CD4066's get more levels.

Yeah, I was wondering about the electrochemistry of a 2 electrode setup too. You'd definitely want the waveform you use to measure the impedance to be charge balanced (waveform integrates to 0 - i.e. equal amounts of positive and negative current) to avoid redox reactions on the electrodes. Even then, the baseline impedance of the electrodes would likely drift a bit over time and require calibration every now and then, but with some silver/silver-chloride electrodes you'd probably be ok for a while.

Of course, since you may not care much about raw impedance versus just a change in impedance as the level rises it may not be too much of an issue.

matho · 12-18-2012, 05:23 AM

Quote:

Originally Posted by MrNatural

Interesting. Do you have any pics of the physical setup? What is max load for the load cells?

Dale

The Max load on the bathroom scales was 150Kg so physically they should be good for that but I have it setup to give me full scale at 102.3Kg

here are some more pics

the 4 load cells removed from the bathroom scales

a jiffy box connected to the underside of the scales containing the instrumentation amp

the complete unit

the unit being tested

and the results

I'm happy with it and its accurate for water in the Hlt and if I know the amount of water going in then I can work out the finished wort volume.

cheers steve

**MrNatural** · 12-19-2012, 06:09 PM

Thanks Steve. Pretty slick setup. My problem is I'm making a "bisexual" rig using electric or propane, or combination of both.

Dale

**crazyirishman34** · 12-20-2012, 12:15 AM

That seams like it would work for setting the strike water in your Mashtun also. It is too bad the Brewtroller can't make a weight correction for the expected gravity.

matho · 12-20-2012, 02:41 AM

Quote:

Originally Posted by MrNatural

Thanks Steve. Pretty slick setup. My problem is I'm making a "bisexual" rig using electric or propane, or combination of both.

Dale

there is no reason you can place the load cells under the burner ( a fair distance away to keep them sake from the heat) and zero the scales before you add the water.

Quote:

Originally Posted by crazyirishman34

That seams like it would work for setting the strike water in your Mashtun also. It is too bad the Brewtroller can't make a weight correction for the expected gravity.

yes you could weigh the mash tun as well, then you could tell when the tun is drained because the weight would stop dropping. I wonder how close you could estimate the gravity by ((weight of liquid out + estimated losses)/weight of water in). Deadspace of the mash tun is easy to know but the absorption rate of the grain would be a bit hit or miss. Maybe when I get some time I'll have a play.

cheers steve

matho · 12-20-2012, 02:43 AM

Also I have had this page bookmarked for a long while but haven't followed up on it

http://www.automatedsonix.com/son40.htm

would be a good way to sense volume but I don't know how cheep it would be

**Gunfighter04** · 12-21-2012, 02:20 PM

Anybody tried one of these yet?
https://www.sparkfun.com/products/9072

**MrNatural** · 12-21-2012, 08:45 PM

Quote:

Originally Posted by matho

there is no reason you can place the load cells under the burner ( a fair distance away to keep them sake from the heat) and zero the scales before you add the water.
cheers steve

DOH

Going HERMS, so could use something like this to maintain MLT weight during sparge.

Quote:

Originally Posted by matho

Also I have had this page bookmarked for a long while but haven't followed up on it

http://www.automatedsonix.com/son40.htm

would be a good way to sense volume but I don't know how cheep it would be

Almost looks plugnplay, but don't see a price anywhere. Probably comes with industrial sized pricetag.

Quote:

Originally Posted by Gunfighter04

Anybody tried one of these yet?
https://www.sparkfun.com/products/9072

I'd like to know that too. Pretty cheap, but only rated to 50°C.
BCS would see that just like a 10K thermistor. Strap it to sightglass, drop in magnetic float and set up custom display for volume.

Brewer Gerard · 12-25-2012, 05:54 PM

Quote:

Originally Posted by matho

Also I have had this page bookmarked for a long while but haven't followed up on it

http://www.automatedsonix.com/son40.htm

would be a good way to sense volume but I don't know how cheep it would be

I managed to rig up an arduino with a HC-SR04 to do level measurement in a keg. It returned a pulse whose width was inversely proportional to the volume of fluid in the keg. Then i got married had a child bought a house and now have less time than marty mc fly

BenS · 12-31-2012, 02:50 PM

http://www.amazon.com/Ultrasonic-Module-HC-SR04-Distance-Arduino/dp/B004U8TOE6/ref=sr_1_1?s=toys-and-games&ie=UTF8&qid=1356968871&sr=1-1&keywords=Ultrasonic+Module+HC-SR04+Distance+Sensor+For+Arduino

I'm using this ultrasonic sensor with my arduino build to tell my unit when to fire the heating element (safe volume level) and when to turn off the heating element if I'm in danger of a boil over. Can't wait to say goodbye to the chance of a boil over while I'm not watching the kettle. Gotta love automation!