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Topic: Pen pH meter care before storage.  (Read 288 times)

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Offline xchcui

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Pen pH meter care before storage.
« on: November 26, 2019, 09:25:38 AM »
Hi.

Due to lack of explanation on google about how this specific type of ph meter works(i mean scientific explanation)and poor manual.
I have some question about this pen ph meter type.
First of all,Is the part that marks with red arrow in the attached photo refer to the reference electrode?
2)Does this type of ph meter also leak electrolyte(or something)into the tested solution during its operation?
3)Regard to the manual(second photo)"OPERATION"part 6-7 sections it says"after finished,clear with D/W and replace the cap".I understand that after i finish to make measurementand before i put it in storage,i need to stir/clean the electrode bulb in distilled water solution and replace the protective cap.But do i need to dry the glass electrode from distilled water residue with tissue(or something)before i replace the protective cap or after i stir/clean the glass electrode in distilled water solution i just replace the cap without touching or drying the electrode?

Thanks.

Offline Borek

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Re: Pen pH meter care before storage.
« Reply #1 on: November 26, 2019, 10:34:47 AM »
Due to lack of explanation on google about how this specific type of ph meter works

In general - exactly the same way every other pH meter does. Many details at http://www.ph-meter.info

Quote
First of all,Is the part that marks with red arrow in the attached photo refer to the reference electrode?

Reference electrode is somewhere behind the junction, that's for sure, but where it is - no idea. Somewhere inside.

Quote
Does this type of ph meter also leak electrolyte(or something)into the tested solution during its operation?

A bit. Typical amounts are way too low to matter, unless you are dealing with some very specific, high purity solutions. But then, you shouldn't use a cheap pen pH meter.

Quote
Regard to the manual(second photo)"OPERATION"part 6-7 sections it says"after finished,clear with D/W and replace the cap".I understand that after i finish to make measurementand before i put it in storage,i need to stir/clean the electrode bulb in distilled water solution and replace the protective cap.But do i need to dry the glass electrode from distilled water residue with tissue(or something)before i replace the protective cap or after i stir/clean the glass electrode in distilled water solution i just replace the cap without touching or drying the electrode?

Don't dry the electrode. Actually leaving a bit of excess water should be a good idea.
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Offline xchcui

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Re: Pen pH meter care before storage.
« Reply #2 on: November 26, 2019, 12:54:17 PM »

Reference electrode is somewhere behind the junction, that's for sure, but where it is - no idea. Somewhere inside.

So,what is this round small part?

Don't dry the electrode. Actually leaving a bit of excess water should be a good idea.
This is the reason why i thought that this ph meter operate in different way.In the manual(not at the one i attached)it says clearly to dry the electrode before replace the cap and it doesn't say anything about store the electrode in storage solution or wet.This instruction was strange,since i read that the glass electrode must be hydrated,while dry electrode won't operate correctly,so i thought it operate in different way(new technology).May you have any idea why it says to dry it?

Offline Borek

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Re: Pen pH meter care before storage.
« Reply #3 on: November 26, 2019, 03:00:01 PM »
So,what is this round small part?

Junction - wick or a glass frit.

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This is the reason why i thought that this ph meter operate in different way.In the manual(not at the one i attached)it says clearly to dry the electrode before replace the cap and it doesn't say anything about store the electrode in storage solution or wet.This instruction was strange,since i read that the glass electrode must be hydrated,while dry electrode won't operate correctly,so i thought it operate in different way(new technology).

The only other technology I am aware of are ISFET electrodes. I can be wrong but last time I checked they were far from being cheap and popular.

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May you have any idea why it says to dry it?

No.
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Offline xchcui

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Re: Pen pH meter care before storage.
« Reply #4 on: November 27, 2019, 08:36:29 AM »
I attached(below)a dismantled pocket ph meter.Can it help in something to answer my questions?
Also,shouldn't the reference electrode that can be seen in the photo,as only a wire,should be cover with a casing and electrolyte?it looks different from ordinary ph meter.

Offline Borek

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Re: Pen pH meter care before storage.
« Reply #5 on: November 27, 2019, 10:23:28 AM »
I wonder if the wire you marked as a reference is not Ag covered with AgCl. If so, it had to be in a small chamber filled with chloride solution, and that would make perfect sense.

Or, it could be just a contact and the reference itself is built into the cap and covered with a glass frit.

How does the removed cap looks like from the inside? How was the wire attached/put into contact?

pH electrode itself looks like a more or less standard glass electrode.
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Offline xchcui

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Re: Pen pH meter care before storage.
« Reply #6 on: November 27, 2019, 11:21:09 AM »
I guess that i won't get a reliable answer,since from your answer,i see that you don't familiar with that type of ph meter.I did my best by sending a dismantle ph meter and also the manual,but if(with all my attachment)it doesn't help,i guess i leave it.
Anyway thanks alot for trying to help and for your replies :)
BTW,the remove cap has nothing special inside.

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