Figured some of you might enjoy seeing how to test methanol with a Hydrometer.
I had to test some that was given to me today...

What does that 790 translate to?

Graydon,
Pics are worth a thousand words...but a little explanation goes a long way too. Is there a right way to read a hydrometer?

In this photo the 100 is % at a specific temperature.

Here's the explanation...
1) Take the temperature of the methanol you're testing
2) Look to see where the hydrometer interfaces with the top of the methanol
In this case, the methanol temperature was 67 deg. F
The hydrometer read .791 to .792
I looked at my table & pure methanol at that temp should be .7917 at 67 deg. F or .7922 at 66 deg. F

So my methanol was very near 100% pure.

I also did a sample of one of the other barrels of methanol.
It's temperature was 61 deg. F.
According to the table I should have had .7949 if it was 100% pure.
My reading was higher (I can't remember exactly what it was).
I did the math between the two & calculated that the methanol was 3% impure (most likely water).

Rick has a really good article on it here:
http://www.make-biodiesel.org/methanoltest/

This is the methanol hydrometer I was using...
http://www.utahbiodieselsupply.../methanoltestkit.php

Handy little sucker to have around....especially when you're trying to determine if the methanol someone gave you is pure enough to use....

-Graydon

Here's a couple better shots (I zoomed in & cropped).

quote:

Originally posted by Graydon Blair:
Here's a couple better shots (I zoomed in & cropped).

If you look closely you will see that the liquid is "forming up" on the hydrometer. We are dealing with very close tolerances on measurements, at least three digits past the decimal. Be sure to read the hydrometer at the level of the liquid in the jar, not the level of the creep up on the hydrometer tube.

Nice jar, Graydon.

Norman

Here's a better shot of what Norm is talking about...

quote:

Originally posted by Graydon Blair:
Here's a better shot of what Norm is talking about...

Please take care as it is possible for the hydrometer to "stick" to the wall of the test vessel and give a false reading

-Paul

Definitely true...
I bobbed mine around until I got it centered when I took the reading.
However, when we drug the camera out, it had wandered over to the side of the vessel and probably was sticking to it.

Great point!
-Graydon

The scientific name for the creeping up effect is "meniscus" link below(if it works)
Nice pics Graydon



en.wikipedia.org/wiki/Meniscus

Nice pics graydon
thank you for posting them