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Biodiesel => Biodiesel equipment => Topic started by: neisel on March 21, 2022, 10:21:50 AM

Title: Hydrometer - is this OK?
Post by: neisel on March 21, 2022, 10:21:50 AM

Never had one, never used one but think I prolly should have one to test methanol. This is advertised for home brewers, will it work OK for bio?

If yes, when I test where on the scale ideally do I want to be if my methanol is good?

https://www.amazon.co.uk/Hydrometer-Included-Millimeter-Trial-Sampling/dp/B0722QYJSZ/ref=sr_1_5?crid=3184IB2TSGHVO&keywords=hydrometer&qid=1647857876&sprefix=%2Caps%2C144&sr=8-5

Ta.

Title: Re: Hydrometer - is this OK?
Post by: DavidA on March 21, 2022, 02:32:52 PM

Hi,

You may find that hydrometer scale a bit cramped.

I have one that measures from 775 to 825. It is very easy to read.

It easily shows the problem of water appearing in your methanol.

I am trying to find out where I got it (years ago) but suspect it is from Stevenson-reeves.

I'll let you know if I can find the details.

Title: Re: Hydrometer - is this OK?
Post by: Julian on March 21, 2022, 05:40:14 PM

Quote from: neisel on March 21, 2022, 10:21:50 AM

... never used one

Yes you have!

Title: Re: Hydrometer - is this OK?
Post by: neisel on March 21, 2022, 05:50:45 PM

David,

Thanks, is this better?

https://www.amazon.co.uk/Dens%C3%ADmetro-alcohol%C3%ADmetro-medidor-alcoh%C3%B3lico-Stevenson/dp/B07KF8Z71K/ref=sr_1_7?crid=EKBBGLZ83WWV&keywords=hydrometer+methanol&qid=1647884436&sprefix=hydrometer+methanol%2Caps%2C108&sr=8-7

Julian,

Don't remember.

Title: Re: Hydrometer - is this OK?
Post by: countrypaul on March 21, 2022, 06:22:07 PM

You need to look for relatively small amounts of water in methanol, so really you need to cover the 90-100% alcohol range. The density of methanol is around the 0.8 mark depending on temperature (it is quite sensitive) - Graham Laming's site has a table documenting purity against temperature with resulting densities reproduced here: http://biopowered.co.uk/wiki/Testing_methanol_purity

Something like: https://www.fishersci.co.uk/shop/products/range-finder-hydrometer-5/12841428#?keyword=hydrometer

Title: Re: Hydrometer - is this OK?
Post by: DavidA on March 21, 2022, 07:36:03 PM

neisel,

Here are a few more details on the hydrometer I suggested.

http://stevenson-reeves.co.uk/hydrometers/LANS.htm

And

Title: Re: Hydrometer - is this OK?
Post by: Julian on March 21, 2022, 09:16:54 PM

Quote from: neisel on March 21, 2022, 05:50:45 PM

Julian,

Don't remember.

You borrowed mine ... a long time ago!