pH meter recommendation, please.

"Richard Knoppow" wrote

Thank you, this and your other posts have pretty much
clarified the issue. I also wrote about using test papers
before reading your note about their low accuracy.

Color-change pH indicators are of low accuracy compared to
pH meters - though on the whole maybe more reliable:
easier to keep something dry than wet; drop a roll of
test paper it and there is no tragedy; you can touch
it; power failures don't throw the calibration off whack ...

An awful lot of chemistry has been developed and executed
without the aid of a pH meter. Colorimetric titration
[the 'wet' version of pH paper] was still common when
I went to University. Repeatability is normally more
important than accuracy. To that aim, always examine
pH paper under the exact same lighting conditions.

Photo chemistry is pretty forgiving: if yesterday's coffee
with a spoon of baking powder can develop film then it is
far from rocket science, more like DIY firecrackers (let's
see: glycerin and permanganate, ammonia and iodine, ...).

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
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