safe uses of pH meter

[PedroSanchez]

i have searched high and low here and across duckduckgo but for some reason i cant find any information on this.

i have just bought a cheap digital pocket pH meter (for other purposes) and i was wondering how safe it is to use for things like DMT extractions.
the type i have bought is similar to the following picture. it is not that exact one, but one of those cheap types:

it has not arrived yet but i can clearly see the tip is mostly made of plastic. i know that most plastics are not safe to use during extractions with lye so i am guessing this is not safe to use to test my lye solutions?

i will, of course, default to it being unsafe until i can prove otherwise, but i feel like people are probably using these meters without problems, or maybe with minimal problems that they are unaware of.

are these meters safe to be putting into our solutions without problems? or are they dissolving slowly every time we use them in the wrong liquids?

some insight would be great because it seems nobody else wants to talk about it.


thanks guys

 

[Elrik]

I don't use that kind, but it's the probe sensor that is most likely to be harmed by lye or strong acids. Even the fancy meters are not meant to be used for very high pHs because of damage to the sensor. My meter was €100 on sale, so I always use pH papers to estimate pH when its in the 12-14 range and my lab meter is for fine precision at pH levels that wouldn't burn me.
Compared to the sensor, the plastic should be impervious to acids and bases. It's traces of solvents like xylene and acetone that hurt the plastic. Even on my nice 3-point calibrated entry level lab meter the plastic probe body is frosted from contact with residual solvent traces when I'm titrating mescaline and DMT out of xylene. Damage to the plastic should be cosmetic unless you get extremely sloppy and the plastic melts or warps.
Acetone would be especially bad.

 

[Loveall]

I've had no issues with that kind of pH meter and A/B extractions except once when acetone was involved (oops).

Even a little acetone will damage it, other than that it works well.

Eventually, the stabilization time to read a pH increases or it just breaks, but for the price it lasts quite a bit I think.

 

[PedroSanchez]

thank you for the replies.

sounds like i should just get a load of pH paper and stick to using that for extractions etc
are there any unsafe uses with pH paper?

thanks

 

[Elrik]

The dyes in pH paper are not intended for consumption, and in fact some are known to be bad for you. Try to avoid getting the stuff inside you
What I do is I buy one of those cheap packs of 1-14 papers and, wearing gloves to avoid contaminating them, I use clean scissors to cut them up the short way across to 2 mm wide strips that are the 8 or whatever mm long. I then keep these 'barbie pH strips' in a jar and use tweezers to use them, just barely tapping an end against an aqueous solution or, when salting out stuff from xylene, I use a pasteur pipette with a eye dropper bulb on the end to grab a sample of the water layer to test.
Not only does cutting up the papers like that turn each paper into around 20, but it also reduces how much of that indicator will get into your stuff.

 

[PedroSanchez]

awesome, thank you so much! thats really useful to know!

i love the name "barbie pH strips" :lol: that will be the label on the jar i store them in then! hahah
i think i will try to take a sample and use that to test, then discard, wherever possible. no harm in using "barbie pH strips" for those samples too, i love the idea of getting 20x the amount

thank you very much for the help