How to test an alcohol hydometer for accuracy

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Rod
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How to test an alcohol hydometer for accuracy

Post by Rod »

How to test my alcohol hydrometer for accuracy

I think my hydrometer is not reading correctly

I have checked my neutral and 100ml weighs in at 87 grams

I do not have any spirit which I can be sure of the alcohol content

I can buy a new hydrometer , but do not want to spend if my current one is right

the beer hydrometer is easy , use water

I have done a google , not much help
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Re: How to test an alcohol hydometer for accuracy

Post by thecroweater »

if you buy alcohol in which to test it makes sure its not sweetened so forget port or pretty much any rum, these will surely throw your reading off. I have three different sized ones so I am sure mine are fairly damn close
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Re: How to test an alcohol hydometer for accuracy

Post by skow69 »

If your 100 ml weighs 87.00 gm at 20.0C, then the purity is 87.4% ABW according to the tables linked by HDNB here, which is 91.33% ABV according to alco-dens.
What does your hydrometer say?
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Re: How to test an alcohol hydometer for accuracy

Post by Yummyrum »

You can certainly test the Zero% in water ....just make sure its at 20 degC or what ever your Alc meter is calabrated at .

Once you know the Zero is right , you can check the reading of store bought but like Crow said , don't use a liqueur as the sugar in it will stuff the readings . Just buy like a 125mL bottle of cheap 40% Vodka and check that it measures 40% @ 20 degC or that ever your alc meter is calibrated at .

Interestingly , "Diggers " brand Methylated spirits here in Australia will show up as 100% ABV .....so that's another way to check full scale reading accuracy ......just give your test jar and meter a good rinse afterwards :moresarcasm:
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Re: How to test an alcohol hydometer for accuracy

Post by Still Life »

I've used 70% isopropyl alcohol out of the first aid kit.
Right on the money.
Wash cylinder and meter well afterwards.
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Re: How to test an alcohol hydometer for accuracy

Post by der wo »

skow69 wrote:If your 100 ml weighs 87.00 gm at 20.0C, then the purity is 87.4% ABW according to the tables linked by HDNB here, which is 91.33% ABV according to alco-dens.
What does your hydrometer say?
Here
ethanol_wasser.pdf
(12.66 KiB) Downloaded 169 times
0.87 is around 76.6%abv.
Still Life wrote:I've used 70% isopropyl alcohol out of the first aid kit.
Right on the money.
Wash cylinder and meter well afterwards.
Isopropyl alcohol and ethanol don't have the same specific gravity. Isopropyl 0.78, ethanol 0.79. What results in a false reading of about 6vol% with spirits at drinking strength.
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Re: How to test an alcohol hydometer for accuracy

Post by Still Life »

der wo wrote:
Still Life wrote:I've used 70% isopropyl alcohol out of the first aid kit.
Right on the money.
Wash cylinder and meter well afterwards.
Isopropyl alcohol and ethanol don't have the same specific gravity. Isopropyl 0.78, ethanol 0.79. What results in a false reading of about 6vol% with spirits at drinking strength.
Thanks, der wo, for keeping me straight. [I had measured 70% on the button, so I didn't suspect gravity differences.]
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Re: How to test an alcohol hydometer for accuracy

Post by der wo »

So you have probably a little less abv than 70 when it says 70.

Edit: No! The opposite. You have more abv.
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Re: How to test an alcohol hydometer for accuracy

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der wo wrote:
skow69 wrote:If your 100 ml weighs 87.00 gm at 20.0C, then the purity is 87.4% ABW according to the tables linked by HDNB here, which is 91.33% ABV according to alco-dens.
What does your hydrometer say?
Here
ethanol_wasser.pdf
0.87 is around 76.6%abv.
Thanks der wo.
Actually, it's 76.06 according to the expensive blending software.

I must be reading the Canadian chart wrong somehow. It still looks like 87.4 to me.
TEMP DENSITY
-20.0 869.2 1.1968 87.7 1.0400
-20.0 869.4 1.1965 87.6 1.0400
-20.0 869.6 1.1962 87.6 1.0400
-20.0 869.8 1.1959 87.5 1.0400
-20.0 870.0 1.1956 87.4 1.0399
-20.0 870.2 1.1953 87.4 1.0399
-20.0 870.4 1.1950 87.3 1.0399
-20.0 870.6 1.1947 87.2 1.0399
-20.0 870.8 1.1944 87.2 1.0399
-20.0 871.0 1.1941 87.1 1.0398
-20.0 871.2 1.1938 87.0 1.0398
-20.0 871.4 1.1935 87 1.0398
-20.0 871.6 1.1932 86.9 1.0398
-20.0 871.8 1.1929 86.8 1.0398
-20.0 872.0 1.1926 86.8 1.0397
-20.0 872.2 1.1924 86.7 1.0397
-20.0 872.4 1.1921 86.6 1.0397
-20.0 872.6 1.1918 86.6 1.0397
-20.0 872.8 1.1915 86.5 1.0397
-20.0 873.0 1.1912 86.4 1.0396
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Re: How to test an alcohol hydometer for accuracy

Post by HDNB »

the temperature you are using is -20C on the chart. scroll down a few thousand entries and find 20C without the - in front of it.

only in Canada does it matter what the density is at -20 :lol: :lol:

I have recently had the opportunity to test my $10 brewhaus proof and tralles against a http://www.stevenson-reeves.co.uk/" onclick="window.open(this.href);return false;" rel="nofollow
$180 for legal trade alcometer, and it's dead nuts on....only that i need reading glasses to see it. The really spendy one has huge graduations which is nice...and it measures in kg's/m3 so you need that fancy chart from the gooberment and a $300 thermometer too :crazy:

BTW, one of you really smrt scientist types that like proving shit wrong should have a go at that chart and see if you can explain it better than the government.
I did the math, and it makes no sense to me.
say, if you had 10L of 44.4%abv, it would be 44.4% booze and the rest water. add up the weight of 4.44L of ethanol x .789 and 5.66l of H2O x 1 and that should give you the weight of the mix of the two, right?
when i calculate what i thought i knew about math, science an booze...their chart comes out mneasuring about 10% less ABSOLUTE LITRES OF ALCOHOL than what math tell me is there.

i suspect their chart is right, being that a team of scientists made the chart over two and a half years (according to the website) and with all that unlimited funding and the fact they use the chart for collecting taxes...it makes more sense that it's right and my math is wrong. :cry: sadly, i ain't smrt enough to figger it.
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Re: How to test an alcohol hydometer for accuracy

Post by WIski »

HDNB Wrote'
BTW, one of you really smrt scientist types that like proving shit wrong should have a go at that chart and see if you can explain it better than the government.
I did the math, and it makes no sense to me.
say, if you had 10L of 44.4%abv, it would be 44.4% booze and the rest water. add up the weight of 4.44L of ethanol x .789 and 5.66l of H2O x 1 and that should give you the weight of the mix of the two, right?
when i calculate what i thought i knew about math, science an booze...their chart comes out mneasuring about 10% less ABSOLUTE LITRES OF ALCOHOL than what math tell me is there.
This might be what your looking for?

Ethanol-water mixtures have less volume than the sum of their individual components at the given fractions. Mixing equal volumes of ethanol and water results in only 1.92 volumes of mixture.
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Re: How to test an alcohol hydometer for accuracy

Post by HDNB »

no, not the volume rather the weight, as you would calculate it in real world, vs. the algebraic algorithm they developed for the chart
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Re: How to test an alcohol hydometer for accuracy

Post by DeepSouth »

I don't know if this is the problem, but you may have mistyped. The sum of 4.44 and 5.66 is 10.1.
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Re: How to test an alcohol hydometer for accuracy

Post by Danespirit »

Yummyrum wrote:You can certainly test the Zero% in water ....just make sure its at 20 degC or what ever your Alc meter is calabrated at .

Once you know the Zero is right , you can check the reading of store bought but like Crow said , don't use a liqueur as the sugar in it will stuff the readings . Just buy like a 125mL bottle of cheap 40% Vodka and check that it measures 40% @ 20 degC or that ever your alc meter is calibrated at .

Interestingly , "Diggers " brand Methylated spirits here in Australia will show up as 100% ABV .....so that's another way to check full scale reading accuracy ......just give your test jar and meter a good rinse afterwards :moresarcasm:
+1 Yummy

Also, there is a link in my signature, where you can read about this device.

Whenever you make a test, be sure to have the right calibration regarding the temperature (most important).
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Re: How to test an alcohol hydometer for accuracy

Post by HDNB »

DeepSouth wrote:I don't know if this is the problem, but you may have mistyped. The sum of 4.44 and 5.66 is 10.1.
ummm...yeah. :oops: see? we found one problem already. :oops:

that wasn't the real world numbers i was using, they filled a whole sheet of foolscap. (aptly named, no?) my problem was i tried to figure how much booze was in a quantity, say 50L at 44%, when i calculated it it came to 22L of pure (100%) ethanol (simple math right?) but if you use their charts, it is like 19.95L of 100% (what they call absolute alcohol or the theoretical 100%)

maybe i was just overthinking it.
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Re: How to test an alcohol hydometer for accuracy

Post by Rod »

skow69 wrote:If your 100 ml weighs 87.00 gm at 20.0C, then the purity is 87.4% ABW according to the tables linked by HDNB here, which is 91.33% ABV according to alco-dens.
What does your hydrometer say?
my hydrometer reads 72% @ 20 degrees

I do a sugar wash

I had thought something was wrong with my last run , I usually get 85% and the last run was 72%

My current run is giving me the same results , hydrometer reading 82% at the start

which if I adjust is 95% at the start of the run and will be 85% to finish

another bonus as I have just started using marbles as packing , and was disappointed , I had not achieved any gain

loosing my marbles :D

have to get a new hydrometer

looks like we have been drinking the gin at 45% , not 40% :D
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Re: How to test an alcohol hydometer for accuracy

Post by thecroweater »

It does kinda sound like a new alcometer is in order, they can be got on line for a fairly cheap. I don't want to kick anyone's holy cow on this but marbles are the least amount of surface area possible for a given height so your result is no surprise to me. Really for packed reflux stills I found it really hard to beat tightly packed structured copper packing closely followed by plain old scrubbies. No one is drinking product at 95% or even 85% so the only important question to ask is do you think your product can be improved? If so then for sure these things matter, if not why worry. That said personally I'm not a fan of neutral/ vodka pulled off below 90% but that's just me.
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Re: How to test an alcohol hydometer for accuracy

Post by Rod »

thecroweater wrote:It does kinda sound like a new alcometer is in order, they can be got on line for a fairly cheap. I don't want to kick anyone's holy cow on this but marbles are the least amount of surface area possible for a given height so your result is no surprise to me. Really for packed reflux stills I found it really hard to beat tightly packed structured copper packing closely followed by plain old scrubbies. No one is drinking product at 95% or even 85% so the only important question to ask is do you think your product can be improved? If so then for sure these things matter, if not why worry. That said personally I'm not a fan of neutral/ vodka pulled off below 90% but that's just me.
you may find this interesting reading

http://homedistiller.org/forum/viewtopi ... ss+marbles
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Re: How to test an alcohol hydometer for accuracy

Post by thecroweater »

Yep Rod been following it since its inception, hell I nearly got drawn and quartered for suggesting they would improve greatly the surface area and liquid retention by scuffing them . Was kind reluctant to poke my head over the sandbags after that :lolno:
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Re: How to test an alcohol hydometer for accuracy

Post by SaltyStaves »

What did you use to measure the 100ml volume? Some of those homebrew store trial jars are out by a large margin.
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Re: How to test an alcohol hydometer for accuracy

Post by Rod »

Yummyrum wrote:You can certainly test the Zero% in water ....just make sure its at 20 degC or what ever your Alc meter is calabrated at .

Once you know the Zero is right , you can check the reading of store bought but like Crow said , don't use a liqueur as the sugar in it will stuff the readings . Just buy like a 125mL bottle of cheap 40% Vodka and check that it measures 40% @ 20 degC or that ever your alc meter is calibrated at .

Interestingly , "Diggers " brand Methylated spirits here in Australia will show up as 100% ABV .....so that's another way to check full scale reading accuracy ......just give your test jar and meter a good rinse afterwards :moresarcasm:
finally got round to checking my hydrometer with diggers

it was 90% , which seems to be the correction I need

will buy a new one off ebay

thanks Rod
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Re: How to test an alcohol hydometer for accuracy

Post by Yummyrum »

Rod , did you test your one with water ?
I'm wondering if the paper print out inside has slipped .... if so then if your 100% is measuring 90% , water ( 0% ) should show up under the 0% mark by 10% .

I'm curious as to whether your meter was not weighted corectly or the scale moved or was not set right n the first place .
These meters are generally pretty acurate
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Re: How to test an alcohol hydometer for accuracy

Post by skow69 »

HDNB wrote:the temperature you are using is -20C on the chart. scroll down a few thousand entries and find 20C without the - in front of it.

only in Canada does it matter what the density is at -20 :lol: :lol:
OMFG! What a rookie mistake. Of course people need to proof their liquor at 20 below zero. Hell, I do it all the time. :roll:
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Re: How to test an alcohol hydometer for accuracy

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skow69 wrote:
HDNB wrote:the temperature you are using is -20C on the chart. scroll down a few thousand entries and find 20C without the - in front of it.

only in Canada does it matter what the density is at -20 :lol: :lol:
OMFG! What a rookie mistake. Of course people need to proof their liquor at 20 below zero. Hell, I do it all the time. :roll:
when you got a team of government scientists working on it for 2.5 years, they have to be thorough right? Typical government debacle! The excise tax guy that showed me that link said "don't use example 2 with column c and d it doesn't work"... :roll:

i mean, what the hell, they only had two and a half years to work out the bugs.

and the instructions "this document is so large that a normal spreadsheet will not load it, select the temperature range you need and load it into a word processor " :wtf:

my tests show the following to be dead on and easy to understand, i printed out weight/abv/temp chart, i had to tape six or eight pages together but it works on every test i've done. there is other charts here too.

http://www.itecref.com/pdf/OIML_Alcohol ... Tables.pdf" onclick="window.open(this.href);return false;" rel="nofollow

the cdn gov one is nice if you have a large quantity measured in weight of say 40% and you want to figure how many litre you have, but fairly impractical at hobby size, when you can look in the jug and estimate the how much drinking you have to do before making another run. :ebiggrin:
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Re: How to test an alcohol hydometer for accuracy

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Yummyrum wrote:Rod , did you test your one with water ?
I'm wondering if the paper print out inside has slipped .... if so then if your 100% is measuring 90% , water ( 0% ) should show up under the 0% mark by 10% .

I'm curious as to whether your meter was not weighted corectly or the scale moved or was not set right n the first place .
These meters are generally pretty acurate
hydrometer showed zero with water , which is odd , the scale is small at that point with all of the column above the bulb sticking above the water level

the scale on the hydrometer is only .25 cm long at zero compared to 1.0 cm at 90%

the meniscus would be about 5 % at that point

the kitchen scale weighed 100 gram with 100 ml of water , I assume this the meter you refer to
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Re: How to test an alcohol hydometer for accuracy

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Rod wrote:
the kitchen scale weighed 100 gram with 100 ml of water , I assume this the meter you refer to
Nah , by meter , I ment Alcometer ( hydrometer).

It is a mystery that it measures OK with water but is out at the top end so much ....can't explain it .
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