Sciencemadness Discussion Board

pH probe

Gargi - 19-3-2008 at 22:00

What is the principle behind pH probe meter, Can i fill Nacl solution as electrolyte instead of Kcl solution

not_important - 20-3-2008 at 01:20

http://en.wikipedia.org/wiki/Glass_electrode

http://www.faqs.org/faqs/sci/chem-faq/part6/preamble.html


historical

http://www.jbc.org/cgi/reprint/81/3/581.pdf

http://www.biochemj.org/bj/027/1069/0271069.pdf

dann2 - 20-3-2008 at 21:10

Hello,

I read in Wikipedia that a pH probe should be stored in 0.1M HCl.
Is this the way with all pH probes? Dont do it with mine.
Also, is hypochlorite severe on pH probes? (Chlorate cell).

Cheers,
Dann2

[Edited on 21-3-2008 by dann2]

MagicJigPipe - 20-3-2008 at 21:24

I found this at the bottom of the Wikipedia page. This shows you how to build a simple pH meter. Then all you need is a pH probe. Damn it's sexy!

http://www.66pacific.com/ph/ph.aspx

Also, why not just use KCl? It is readily available OTC and extremely inexpensive!

[Edited on 20-3-2008 by MagicJigPipe]

Gargi - 20-3-2008 at 23:42

Thanks for the responses, Actually the KCL solution in the pH probe has dried out below the specified level and therefore the question, anyway the job is done with saturated KCl solution.

dann2 - 22-3-2008 at 15:30

Hello,
2 more cents worth.
pH probes have very very high output impedence. I remember a project for a pH meter where they stressed the need to use high quality board (for holding the components) because low quality/cheaper (phenolic based) boards would have a significant conductance between the input pins (coming from probe).

Dann2

Drunkguy - 2-4-2008 at 07:44

I got one myself recently.

Obviously I had pH papers already which are perfectly okay so long as they are put back into their container afterwards.

What you find on Ebay is these Hong Kong suppliers who "spam" the things until you buy them.

I also bought 3 electronic balances due to similar circumstances. They work GOOD though :cool:

The pH meter I spent £10.99 TOTAL but I havent tested it yet. I still need buffer solutions and deionized water before I can test it.

[Edited on 2-4-2008 by Drunkguy]

jimwig - 3-4-2008 at 06:52

i got something along this line and it goes like this

i recently bought a accumet analog ph meter and the socket connecgtion is a 1/4 inch jack type - as opposed to bnc types with the more modern.

anyone with experience on the older stuff. as in will the newer probes work by just changing their connector? i can make my own probe via ref on JCE page.

well i can't find the jce article right now. of course but its there.