Using pH meter to adjust electrolyte mix?

[Lasse94]

Do you think it's possible to use a pH meter to correctly mix KOH/NaOH ratio?
It would have been quite easy to adjust right if you don't have an amp meter?
Thanks ;)

[BioFarmer93]

Do you think it's possible to use a pH meter to correctly mix KOH/NaOH ratio?
It would have been quite easy to adjust right if you don't have an amp meter?
Thanks ;)

Lasse,
Yes, it is possible, and some people do it that way. If you research this forum's archives you will find some references to the proper pH for a 28% KOH solution. The 28% solution is considered optimum because it passes the maximum current. You may use a stronger solution but there is no gain in production, and you will be wasting KOH.

[Bazarommcmullen]

Is the same 28% solution ideal for the Lye as well?

[Lasse94]

Thanks for answering guys! i thought i was the first one to try it though :rolleyes:
is it 28 % for lye aswell? :)
Thanks!

[BioFarmer93]

Is the same 28% solution ideal for the Lye as well?

No. I think I remember it being around 20%, but I'm not sure...

[myoldyourgold]

Is the same 28% solution ideal for the Lye as well?

NO NaOH max is 20% over that things start going down hill. KOH is 28%

[Bazarommcmullen]

Is this measurement 20% by weight? I know I should search this site for previous discussion just thought I'd ask the question here while the topic is discussed.

[myoldyourgold]

Is this measurement 20% by weight? I know I should search this site for previous discussion just thought I'd ask the question here while the topic is discussed.

Yes it is by weight. It can be measured by a hydrometer. Cheap ones are used to measure the SG of battery acid. Here is a link for NoaH specific gravity by %

http://www.handymath.com/cgi-bin/naohtble3.cgi?submit=Entry

[keiththevp]

I addressed this in another thread recently, you can not measure the concentration based off Ph. Do a test yourself with the cheap litmus paper tabs like I did. It only costs 5 dollars for the fish tank ones. Add a small amount of KOH or NaOH to water in one cup then add a lot in another cup, then test Ph, they will both be 13-14.

Now if you are talking about very small concentrations like an 1/8 of a tablespoon in a gallon of water then yes you can use Ph. But any reasonable amount added to actually make gas and no the Ph will always be 13-14

Myold is correct a hydrometer is the only accurate way to measure concentration.

[BioFarmer93]

Keith,
He asked about meters, not litmus paper. It may be erroneous to equate the measurement range and/or accuracy of litmus paper to that of an expensive lab grade piece of equipment.

[myoldyourgold]

Guys lets clear this up a little. Yes you can use an expensive (a relative term)PH (pH is the negative logarithm of the Hydrogen ion activity) meter. Here is one that sells for $910.00 Us but why when you can get a hydrometer for $6.00.

[Roland Jacques]

A PH meter would work for a VERY small amount of KOH. You would see your PH rise then hit a plateau rather quickly and it would not rise much beyond that. The problem is that would probably happen below 1% by weight.

So hydrometer measuring SG would be much more useful. A refractometer is a more accurate version of hydrometer to measure SG. Really a $6 hydrometer is a good tool to have and much more useful than a PH meter

[Roland Jacques]

"Democracy is two wolves and a lamb deciding what to have for dinner. Liberty is a well-armed lamb."


myoldyourgold
That's awesome!!!

[keiththevp]

Keith,
He asked about meters, not litmus paper. It may be erroneous to equate the measurement range and/or accuracy of litmus paper to that of an expensive lab grade piece of equipment.

I agree, but I was thinking in terms of what most people can afford.:D

[BioFarmer93]

...as obviously I was not. Seems the point may be moot anyway, as the ability of pH meters to measure alkalinity sounds like it runs up against a wall not far from home base:rolleyes:;)