# How quickly have you replaced the probe on your pH meter?



## geek (Nov 23, 2016)

I have the Milwaukee PH56 meter, purchased around 3 1/2 years ago.
I had posted a question about the metter not locking into the 4.01 solution at 4.01 but around 3.97

I ran out of 7.01 solution but decided to check the meter last night in the 4.01 solution and it is coming up at 3.75

The guy at Milwaukee emailed me saying that the life expectancy of the meter probe is around 10~12 months and that mine has aged out.

That life expectancy seems to be short???

What's your experience?

The cheapest I found for this probe is ~$32.00 shipping included, a new PH56 meter is about $59 shipping included.

If I rather buy a new one, better than buying the probe, or better to get a different meter with a better life expectancy?


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## ibglowin (Nov 23, 2016)

I don't own a Milwaukee but have owned a Hanna pHep 5 for 5 years now. No problems. Last season I noticed the probe was looking pretty cloudy so I bought some probe cleaning solution and cleaned the probe as directed. Rechecked wines and went about my business. This fall I checked a bunch of pH's and they seemed low. Cleaned the probe again and recalibrate and rechecked. No change. Bought a new replacement probe from Hanna as I thought this can't be right. New probe was $50 shipped. Swapped the probe out, recalibrated with fresh buffer solution and rechecked all the wines.........

Exact same pH to within +\- 0.02

So I don't think there was anything wrong with my probe and it was 5 years old. 

12 months seems way too short especially with limited use. The only way to really rule out a faulty probe is to buy a replacement probe or buy another complete unit so you have a backup to compare numbers.


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## stickman (Nov 23, 2016)

I have the Oakton model 30, the last electrode replacement was 3 yrs ago and it is still working well. I do have a spare sensor on hand as I think I'm on borrowed time. Most manufacturers of these small hand held PH meters only give a 1yr life expectancy on the sensor, but in practice the life largely depends on the usage and storage. The longer the tip is in contact with a sample while taking a reading, the shorter the life will be. The sensor tip should be stored wet with storage solution, if you use anything other than storage solution, the life will be shortened. Normally it is not recommended to store the tip dry, but I have accidently allowed it to dry several times with no negative effects other than having to soak in storage solution for an hour or so.


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## geek (Nov 23, 2016)

ibglowin said:


> I don't own a Milwaukee but have owned. Hanna pHep 5 for 5 years now. No problems. Last season I noticed the probe was looking pretty cloudy so I bought some probe cleaning solution and cleaned the probe as directed. Rechecked wines and went about my business. This fall I checked a bunch of pH's and they seemed low. Cleaned the probe again and recalibrate and rechecked. No change. Bought a new replacement probe from Hanna as I thought this can't be right. New probe was $50 shipped. Swapped the probe out, recalibrated with fresh buffer solution and rechecked all the wines.........
> 
> Exact same pH to within +\- 0.02
> 
> ...



I am having similar issue, all my wines (except for the PS from fall last year) seem to be in the low side, one batch reading at 3.17 and the other in the 3.24
The most recent that finished MLF started around 3.47 after alcoholic fermentation and then after MLF it shows in the 3.35.
My chilean batch from last year is the one at 3.17 and it was 3.46 2 months ago after coming out of the barrel.

So I am really not trusting this meter at all, although the wine tastes a bit harsh which may be an indication of high acid.

Anyhow, I think I am going to take the plunge and order a new probe.


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## geek (Nov 23, 2016)

stickman said:


> I have the Oakton model 30, the last electrode replacement was 3 yrs ago and it is still working well. I do have a spare sensor on hand as I think I'm on borrowed time. Most manufacturers of these small hand held PH meters only give a 1yr life expectancy on the sensor, but in practice the life largely depends on the usage and storage. The longer the tip is in contact with a sample while taking a reading, the shorter the life will be. The sensor tip should be stored wet with storage solution, if you use anything other than storage solution, the life will be shortened. Normally it is not recommended to store the tip dry, but I have accidently allowed it to dry several times with no negative effects other than having to soak in storage solution for an hour or so.



Before this past August, I always stored it with spring water, then started using storage solution, which BTW creates like an icing cake on the small plastic container I used to just leaving the meter cover off. This time I will put the storage solution in the tip and place the meter in it.

I am now thinking what Mike said about cleaning the electrode, I never used anything except for tap water to rinse the unit but I know it has stains from red wine, so also wondering if maybe buying some cleaning solution first and see what happens.


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## Johny99 (Nov 23, 2016)

IMHO 90% of the meter is the probe. I think you get what you pay for. I have a had quality probe that is over ten years old, still working great. Store in storage solution, keep it clean I use di water, clean every year or so, keep it topped of, and they last really well. There are rejuvenating kits that can work if it isn't too far gone, but they are about $50 so cheaper to replace a low price probe than bring it back. My atc probe is like $200 so worth it for that one.


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## geek (Nov 26, 2016)

Just got my new supplies today including cleaning solution.
For how long you put the pH meter in cleaning solution? I got no instructions and nothing online that tells exactly how to use it.

I put the meter in the cleaning solution for about 4 minutes but wonder if it can be in it for many hours..


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## Johnd (Nov 26, 2016)

geek said:


> Just got my new supplies today including cleaning solution.
> For how long you put the pH meter in cleaning solution? I got no instructions and nothing online that tells exactly how to use it.
> 
> I put the meter in the cleaning solution for about 4 minutes but wonder if it can be in it for many hours..



These are the Hanna instructions found online:

The pH electrode should be cleaned periodically. A coating will form on the glass bulb that will cause errors in measurements and drifting/erratic readings. A typical cleaning procedure is to place the electrode in a cleaning solution for 15 minutes. After that the probe is rinsed with purified water and then placed in storage solution for at least 2-3 hours before using. It is important to note that there are many different types of cleaning solutions available based on the application. Solutions include ones for proteins, inorganics, food and wine stains to name just a few.

And this excerpt from the Milwaukee Q & A sheet:

Q. My pH meter has a little mold or dirt on the white strip and bulb will that affect the performance?
A. Yes, you can clean the probe in MA9016 pH cleaning solution or white distilled vinegar: Put the probe in full strength for 10 min. stirring gently then rinse well in tap water and let sit in Storage solution or 4.0/7.0 50-50 mix or Bottle Drinking Water ( RO water ) for 2 hours and then recalibrate.


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## geek (Nov 27, 2016)

Thanks John.


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## geek (Nov 27, 2016)

I can see the little bulb is stained so time to try white vinegar then if cleaning solution doesn't remove it.


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## ceeaton (Nov 27, 2016)

Johnd said:


> And this excerpt from the Milwaukee Q & A sheet:
> 
> Q. My pH meter has a little mold or dirt on the white strip and bulb will that affect the performance?
> A. Yes, you can clean the probe in MA9016 pH cleaning solution or white distilled vinegar: Put the probe in full strength for 10 min. stirring gently then rinse well in tap water and let sit in Storage solution or 4.0/7.0 50-50 mix or Bottle Drinking Water ( RO water ) for 2 hours and then recalibrate.



Thannnnnnnk you John! The cost difference between the white distilled vinegar and the MA9016 may buy me a cheap case of beer. Never thought of a 50/50 mix of the 4.01/7.01 solutions to store it in (or the RO water which I have about 8 gallons of right now (for my fish tanks)). Thank you again! You're my hero.


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## Johnd (Nov 27, 2016)

ceeaton said:


> Thannnnnnnk you John! The cost difference between the white distilled vinegar and the MA9016 may buy me a cheap case of beer. Never thought of a 50/50 mix of the 4.01/7.01 solutions to store it in (or the RO water which I have about 8 gallons of right now (for my fish tanks)). Thank you again! You're my hero.



You are quite welcome Craig. Whooda thunk I'd achieve hero status with a few keystrokes on Google!


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## stickman (Nov 28, 2016)

I think the RO water would be the last choice of the three suggested. The idea of a storage solution is to provide a liquid that is similar to the probe's internal electrolyte. Use of anything different in composition or concentration causes a slow but steady loss of internal electrolyte. It may not be a real big issue, but that's the concept anyway.


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## geek (Nov 29, 2016)

Finally got my supplies, used cleaning solution and also used white vinegar. Although the stain is still present on the bulb, the meter seem to calibrate ok but took a long time reading in the 7.01 and then also in the 4.01 solution.

Before the calibration, the wine batches were showing a low pH but now they show a higher pH than before, I mean much higher 

I will recheck one more time later tonight, but man what a big swing...


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