Inline ethanol % meter

Kye · Post by **Kye** » Sun Jul 08, 2007 6:15 pm

Hi
Im currently working on a meter to measure and record the ethanol concentration in the spirits comming off my still. It will be based on the capacitance between two probes immersed in the liquid. Has anyone tried this before? Any ideas if it will work?

Thanks
Kye

new_moonshiner · Post by **new_moonshiner** » Sun Jul 08, 2007 7:21 pm

http://homedistiller.org/forum/viewtopic.php?t=4523

Kye · Post by **Kye** » Sun Jul 08, 2007 7:59 pm

Yeah i saw that one but im thinking of using capacitance rather than electrical conductivty.
The dielectric constant of water seems to be about three times that of ethanol so im hoping that a cheap multimeter will be accurate enough to give a useful reading.

Post by **theholymackerel** » Mon Jul 09, 2007 5:28 am

There already is a cheap , accurate, tool for this purpose... it's called a hydrometer.

Nykter · Post by **Nykter** » Mon Jul 09, 2007 7:07 am

theholymackerel wrote:There already is a cheap , accurate, tool for this purpose... it's called a hydrometer.

Thats exactly the attitude thats too common on this forum, which is preventing at lest me to participate more. "There is only one correct way of doing things. Ours." This seriously stops all forms of research and new inventions being discussed here.

Kye, that sounds really interesting. I dont think you should expect a very exact measurement, but you will definitely have a hint on whats going on.
How will you create the "capacitor" with the fluid as dielectricum? Two isolated electrodes immersed, or maybe a sort of chamber with the electrode as opposing walls, or some arramgement with a pipe between electrodes?

I have had thoughts of attaching an optical sensor, or maybe a coil and magnet to a hydrometer. I am now and then experimenting with a contiuous stripper, with the need of such a device to be able to computer monitor the product from it.

Post by **Uncle Jesse** » Mon Jul 09, 2007 7:13 am

I agree, hydrometers are available and cheap and if you want one which is NIST calibrated you can get one rather easily.

I'm not saying don't try to do it, but I am saying it's not something that I'd spend a lot of time and effort making.

Post by **theholymackerel** » Mon Jul 09, 2007 11:44 am

Wow.

I wasn't tryin' to upset anyone Nykter. If you wanna try and make somethin' like that purely for the enjoyment of it, go right ahead.

I, myself, don't waste time or money re-inventin' the wheel. You might be like a friend of mine. He didn't like the gate valves on his still. So he went down in his basement and spent the whole day machenein' his own needle valves. I asked him later why he didn't walk literally across the street to the plumbin' supply shop. He said that wouldn't have been fun. I then pointed out to him how cheap the valves were across the street and how many hours he spent. Didn't he mind workin' for a few cents an hour? Then he blew up and started yellin'.

I guess this is somethin' like that.

Anyway... I wasn't tryin' to upset anyone. I was just makin' a comment and I think yer overreactin'.

Nykter · Post by **Nykter** » Mon Jul 09, 2007 1:11 pm

Sorry for loosing my head. Mr Mackerel, that wasnt on you. I'm actually happy you brought it up, giving me an opportunity to flame the site a little.

And yes, I did really overreact if you consider this specific topic. You are probably right, it wont work. But, noone knows before it has been tested, and tested in a hobby context.

I have been thinking my response over a couple of hours now and I dont want to take it back. That comment is a perfect summary of the spirit of this site. The site is a goldmine of knowledge in traditional distilling and moonshining, but when it comes to trying something new, it allways runs into a massive resistance and has to be put down.

I have been lurking this site for a couple of years I think it is, and the main reason for not participating more is this spirit.

My excuses for the overreaction, but I couldn´t find any other way to express myself in this subject.

Back to the topic:

Kye please go on testing. Even if all you find out is that it doesn´t work, that is also a step forward. Then we know that. If you dont try, I might...

PS: I have also made a needle valve myself, but that was because I wanted it urgently, and couldnt find it in any store close to me. But probaby I am a little like that friend of yours, I want to do as much as possible myself.

Kye · Post by **Kye** » Mon Jul 09, 2007 4:40 pm

Yeah the reason I dont want to use a hydrometer is so I can hook it up to a computer and automate things a bit.

I rigged a test setup last night by poking the probes of a multimeter side by side into a length of tubing and sucking spirits through it. It gave significantly different readings between just water and ~95% ethanol.

Im planning on putting a more permanent setup together today and try some more dilutions. Ill let you all know how it turns out.

riff42 · Post by **riff42** » Tue Jul 10, 2007 5:30 am

Kye wrote:Yeah the reason I dont want to use a hydrometer is so I can hook it up to a computer and automate things a bit.

I rigged a test setup last night by poking the probes of a multimeter side by side into a length of tubing and sucking spirits through it. It gave significantly different readings between just water and ~95% ethanol.

Im planning on putting a more permanent setup together today and try some more dilutions. Ill let you all know how it turns out.

damn right. not everyone wants tradition.
If you figure out a stable number base (always x for tap water, y for 80 proof, and Z for pure 95%), I'm sure it's easy to map it out. I figure with the PC interfaces they have now, you can get a computer program that will map everything out, as long as you double check the % with a hydrometer.
I'm sure you can sell them once you get a few prototypes workin!

absinthe · Post by **absinthe** » Tue Jul 10, 2007 6:17 am

it might also be an idea to test different types of washes...

the impurity's in the distillate might throw to much variance into the idea...

do your suck test with a rum wash, a straight sugar wash, and a grain wash of the same % and see it the reading is the same

junkyard dawg · Post by **junkyard dawg** » Tue Jul 10, 2007 7:03 am

its probably not that simple...

http://www.anton-paar.com/density-meter ... p.en.0.jsp" onclick="window.open(this.href);return false;" rel="nofollow

agl · Post by **agl** » Sat Jul 14, 2007 9:56 am

Excellent idea!
I made a "refractometer" hollow prism device to measure the refractive index of the distillate, (I used a laser pointer and was going to use a ccd to measure the beam deflection). I didn't yet get around to building one that I could trust in real distilling use (the crude one I made had the glass joined together with epoxy - not safe for drinkable distillate. This idea of measuring capacitance is great, and I will be trying it out since it is less cumbersome than the refractive index measurement. For your permanent setup check out some of the ICs made by Qprox http://www.qprox.com/ onclick="window.open(this.href);return false;" rel="nofollow - Digikey sells them, these are much better for sensitive capacitance measurements than a multimeter, especially for relative, repeatable measurements.
EDIT:
I just checked and, digikey doesn't have the ic- qt300 that is best for such an application, if I find a source I'll post it.
also keeping the liquid electrically isolated from the contacts is critical to preventing problems with conductivity of the liquid. - plates should be better than probes too.
good luck with your project!

byacey · Post by **byacey** » Sat Oct 20, 2007 10:34 am

Measuring capacitance between two electrodes in the liquid will not have much in the way of stable measurements due to conductivite variables of the liquid from residual metals etc.

If you insulate the electrodes from the liquid, the insulation becomes part of the dielectric between the plates of your capacitor, the other part being the liquid. I doubt that the dielectric constant between alcohol and water varies enough to get any repeatable readings either. The problem is further amplified because again the dielectric of the liquid will change due to any conductivity that the liquid exhibits due to the residual metals and salts mentioned above.

I don't want to discourage you from trying, but this is what I know about it, and it doesn't appear to be very useful way of measuring in my opinion.

bcubed · Post by **bcubed** » Wed Oct 31, 2007 4:21 pm

I know that the aviation industry uses capacitance-type fuel gages to correct for the lowered energy density of warm fuel. (This is also why they mesaure fuel in pounds, not gallons.)

Although a direct substution wouldn't be practical here (aviation parts are $$$$), perhaps one could reverse-engineer it...

Post by **Husker** » Wed Oct 31, 2007 4:27 pm

One thing which "could" be done, is to program some software to "watch" a hydrometer (and be tied in with a digital thermometer).

Then, using some pretty simple logic, the program can "watch" and monitor a hydro.

This might be a project I would look at doing (if I ever get a breath of time off). Simple DV camera input, digital therm input, and software that simply watches the "lines" of the hydro.

I think this could be designed MUCH more accurately than some capacitive monitoring system.

H.

pintoshine · Post by **pintoshine** » Wed Oct 31, 2007 8:14 pm

Husker you are a man after my own heart. Automation. Make me lazier than I already am. Next we will have a dial-a-brew for our grain bill and a computerized mashing system. Only thing left is automation for transfer pumps and your camera system pre-programmed to do the cuts.

Just messing with ya.

Post by **Husker** » Wed Oct 31, 2007 8:50 pm

I have been known to spend 100's of hours figuring out, prototyping and designing a system to automate something.

I love turning a 30 minute process, into a .01s process. And yes, laziness is one of my traits also

H.

punkin · Post by **punkin** » Wed Oct 31, 2007 9:25 pm

I am the exact opposite.
My handbrake reckons i'm the only man in Australia that takes 3 hours to cook 4 minute noodles....

Well ya gotta make proper chicken stock

welska · Post by **welska** » Wed Dec 05, 2007 7:26 am

I found a digital hydrometer at: http://www.sundialanalytics.com/" onclick="window.open(this.href);return false;" rel="nofollow

Perhaps a bit pricey when compared to a precision hydrometer (except if you have a partner that is a butterfingers, 8 dead $80 hydrometers and counting).

Based on work similar to what Geoff Redman's "draft" has done on: http://groups.yahoo.com/group/Distillers/files/" onclick="window.open(this.href);return false;" rel="nofollow (Correction Table for Alcoholmeter Calibrated at 20 "degrees" C)

And the federalis: www.ttb.gov/foia/Table_1.pdf

I am looking to (probably via lookup tables as I can't figure out the math to programming issue) build a Temperature Compensated Hydrometer that will provide ABV values for distilled products at or close to room temperature (F). (Looking at the PICAXE microprocessor as a possibility)

Anyone interested in this bit of nonsense?

Off forum email: Brian@tuthilltown.com

Regards,

Brian
Tuthilltown Spirits

Post by **HookLine** » Wed Dec 05, 2007 8:19 am

welska wrote:8 dead $80 hydrometers and counting

Rudi · Post by **Rudi** » Sat Dec 22, 2007 1:19 am

I'd be giving butterfingers another job

Post by **Uncle Jesse** » Sat Dec 22, 2007 10:49 am

I thought about purchasing doubles of all my hydrometers for that exact reason. My partner isn't what I'd call graceful.

riff42 · Post by **riff42** » Thu Jan 03, 2008 5:58 am

punkin wrote:My handbrake reckons

HAAAAAAAAAAAAAAHAHAHHAHAAAAA....
I love it.

Post by **shadylane** » Thu Jan 03, 2008 8:18 am

Seems like a round about way to measure the specific gravity of a alcohol/water solution. But then I've been known to waste time and money to roll a homebrew capacitor out of wax paper and aluminum foil. I wonder how my occasional blue distillate would effect the dielectric constant.

Post by **Husker** » Thu Jan 03, 2008 8:45 am

I guess it would be possible to fabricate a container like a parrot beak, which was put on a digital scale. Then through changes in the mass of the container (its contents actually), one could "tune in" an ABV computation system, just due to specific gravity.

The hard part of this system, would be to be able to maintain "exacting" volumes of distillate, and then "tuning" the thing in to measured ABV. However, if the volume could be stabilized, then this type of system should be pretty accurate.

H.

p_su · Post by **p_su** » Mon Jan 14, 2008 1:19 pm

I've no idea if anyone is working on this anymore... but thought I'd throw in my 2c. Another option for creating an input value from a basic hydrometer would be to put it into a parrot's beak - and then affix a target to the top of it. A laser rangefinder or similar device could then measure the height of the hydrometer, when placed above it. Calibration could be done in software.. and that should be a very repeatable result.

Post by **Husker** » Mon Jan 14, 2008 2:08 pm

p_su wrote:I've no idea if anyone is working on this anymore... but thought I'd throw in my 2c. Another option for creating an input value from a basic hydrometer would be to put it into a parrot's beak - and then affix a target to the top of it. A laser rangefinder or similar device could then measure the height of the hydrometer, when placed above it. Calibration could be done in software.. and that should be a very repeatable result.

Nice idea.

I actually wrote compute software in the early 90's which used a device that had two spinning laser hubs and multiple retro reflective targets which the lasers would bounce light off of, and detect where the targets were. These targets were then hung off of "reference" points on the frame and other carriage points of damaged vehicles, and then IN REAL TIME, a frame technician could bend the auto frame back into proper shape (and computer graphics would show just how much damage was in each part of the frame as the process went forward). The project I worked on (called Genesis) was years ahead of ANY other measurement system. Most other measurement systems used a fixed "framework" that had to be put together, lifted up to the frame, measurements taken, and then the framework moved out of the way, for the next "frame adjustment" to be made. A very slow process.

This form of measurement (laser transmitter/receiver with a reflective target) would work GREAT for monitoring the height of a hydro. In that case the math is TRIVIAL. You are only monitoring 1 target, and only dealing with a simple 1 dimensional computation (vs a 3 dimensional computation on multiple targets).

It is surprising how having different people group brainstorm can cause some really impressive options to be put forward.

H.

corndawg · Post by **corndawg** » Tue Apr 22, 2008 6:50 am

Uncle Jesse is right the hydrometer is cheap and accurate. I did see were some one made a simple tube, big enough to float your hydro(maybe 3/4") with a smaller tube sweated to the bottom of the larger bent upward to above the top of the main tube with a brass fitting (for catching) and an overflow tube sweated to the top of the main tube for product collection. this will give you an accurate realtime reading.

trthskr4 · Post by **trthskr4** » Wed Apr 23, 2008 2:57 pm

Aircraft do use a similar set up. It is basically 2 conductive cylinders, one inside the other set at a particualr spacing between, which are mounted from the bottom of the fuel tank to the top. A small electrical charge is placed on one side and the dialectric constant will always read the same in pounds. (aircraft measure fuel in pounds if you didn't already know). A reading is taken in the picofarad range and induced via amp to the gauges. It is quite sensitive and uses all coaxial cabling to shield out stray voltages which would offset the readings. The smaller charge is used as to not BLOW UP the plane, jet fuel has a tendency to burn as does Ethanol, so BE VERY CAREFUL. I can neither confirm nor deny how I know this. I personally wouldn't like to be the pioneer in this endeavor but might I suggest you use as test fuel an abv lower than 50%. Start at maybe 40% and make your calculations down to 0%, then start upward from 40% to say 90%. I would much rather light up 100mls of 50% than 100mls of 90%. Either way fire is hot.

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