Pocket pH meter storage

Thread Starter

xchcui

Joined May 12, 2014
139
ph meter yellow.jpg
Hi.
At the attached photo you may see a type of pocket pH meter.
On the following link you can see the pH meter dismantled:

https://www.allaboutcircuits.com/news/teardown-tuesday-digital-ph-meter/?cb=1574800939
The manual says:when you finish the measurment,you need to clean/stir the electrode bulb with distilled water,
DRY the electrode bulb and replace the protective cap before store the ph meter.
As far as i know,ph bulb electrode should be stored wet or be in a storage solution.
Could it be that this type of ph meter has a different technology/operation?

Thanks.
 
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jpanhalt

Joined Jan 18, 2008
8,346
That looks like a conventional pH electrode bulb to me. Given its location, I don't see how one could dry it easily, but given the way it is packaged, one might anticipate problems related to the high humidity from storing it wet.

Too bad the "tear down" didn't mention anything about function. Seems like more than a little oversight to me.
 

SamR

Joined Mar 19, 2019
1,508
We always cleaned them and stored them suspended in a beaker of distilled water kept in a closed vent hood to prevent contamination of the water. That would not be practical for that model.

Edit: After looking at the Cole-Palmer link it jogged my memory. We suspended them in pH 7 buffer for storage, not distilled water.
 
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Thread Starter

xchcui

Joined May 12, 2014
139
That looks like a conventional pH electrode bulb to me. Given its location, I don't see how one could dry it easily, but given the way it is packaged, one might anticipate problems related to the high humidity from storing it wet.
The manual says to suck gently the water from the electrode bulb with filter paper.What problems may occur if storing it wet?
Is this ph meter,also,leak some kind of electrolyte to the
tested solution in its operation(as the regular ph meter)?
Also,in the attached link the reference electrode that can be seen in the dismantle ph meter is just a wire without any casing,is it made like that or maybe the casing of the reference electrode broke when he dismantle the ph meter?
 

atferrari

Joined Jan 6, 2004
3,581
First time I hear those electrodes are kept wet and not dry. Surprising to me.

Look around paying attention and you learn things every day! :D
 
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Thread Starter

xchcui

Joined May 12, 2014
139
Jpanhalt,thanks for your reply,but i think that all your
links refer to non pocket ph meter.
Lets put the dry issue aside and focus on my other question:

Is this ph meter,also,leak some kind of electrolyte to the
tested solution in its operation(as the regular ph meter)?
Also,in the attached link the reference electrode that can be seen in the dismantle ph meter is just a wire without any casing,is it made like that or maybe the casing of the reference electrode broke when he dismantle the ph meter?
What is the small round part that i marked with a red arrow(in my attached photo)?it looks like the end of the reference electrode,but i am not sure.
 

SamR

Joined Mar 19, 2019
1,508
pH measurement is an arcane black art. I did it several times a shift as an analytical chemist but as a process control engineer, we had a real headache of a problem doing an onstream analysis of some very nasty acidic wastewater that had to be neutralized before being sent to the cities wastewater plant. They got a bit irate when we killed the "bugs" in their wastewater digester with our acidic waste. We went through probes like popcorn at the theater. Ended up pulling and calibrating/replacing probes every 4 hours.
 

Thread Starter

xchcui

Joined May 12, 2014
139
...Since technical information on that meter is limited to the link you provided, perhaps its author (@NickDavis) can address those questions.
I can't see any way to make with him a contact about this question.Its article was written 2 years ago.
Anyway,jpanhalt and Samr,thanks for your replies.
I just a little bit disappointed that you couldn't answer at least to one of
my question,but thanks again for trying:)
 
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jpanhalt

Joined Jan 18, 2008
8,346
@xchcui

It's not that I can't answer that question with respect to typical analytical pH meters, it is that your meter is apparently special and may not be subject to the usual approaches.
 
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