Milwaukee PH56 pH meter

[geek]

I tried to calibrate my ph56 meter and here's what I get:
-7.01 solution says REC and then USE
-I then put into 4.01 solution, here the 4.01 REC and then WRNG message comes up (spelling)
-then it reads 4.01 REC and stays there for a few seconds
-it finally comes up calibrated to 4.00
-however, I leave it in the 4.01 solution and after a couple seconds it reads 3.98

This solution should not be old, over 6 months but less than a year
I never use the storage solution (mistake?) but leave probe in spring water with the cap

Tried this twice and same thing happened.

Do I need to add .02 to my pH readings since it is calibrating below the 4.01?

NOTE: when I turn it on while in the 7.01 solution it reads 7.06, so I know it is not really calibrated and off by .05 decimal.

Thoughts?

 

[cmason1957]

Is this a new meter or an old one? If new is it possible you need a new probe?

 

[geek]

Sort of old one, maybe over 2 years old.

 

[ceeaton]

May want to try storing it in the 4.01 solution. The spring water is probably closer to the 7.01 solution, and that might be your problem.

 

[Julie]

I'm thinking you need a new probe

 

[Johnd]

Try getting some probe cleaning solution and get it cleaned, store it in the storage solution. I spilled my storage solution and stored in my 4.01 buffer for a while and had some unexplained variability. Straightened out once I got back into storage solution, FWIW.

 

[geek]

Where is everyone getting pH meter solution from?
The cleaning and storage solution at Label Peelers is like 230ml and I'd like something smaller for the time being, especially the cleaning solution.

Don't see or can't find at MoreWine in smaller size.

 

[ibglowin]

DO NOT STORE THE PROBE IN ANY SOLUTION OF H2O!!!!!!!!!!!

NEVER STORE THE pH ELECTRODE IN PURIFIED WATER

Storing the pH electrode in purified water (RO, DI, or distilled) will shorten the life of your pH electrode.

The reference cell has a high salt solution. Placing the probe in purified water will cause the salt to diffuse out and the water to go in. Storage solution is not only formulated to maintain the reference salt concentration but also has chemicals to keep bacteria and fungus from growing. If storage solution is not available then use pH 4 buffer.

 

[geek]

I will get some storage solution but I was just looking at this manual online and it says bottle drinking water can be used?


http://www.milwaukeeinstruments.com/site/pdf/pH55-pH56_Starter_Manual.pdf

DO NOT STORE THE PROBE IN ANY SOLUTION OF H2O!!!!!!!!!!!

NEVER STORE THE pH ELECTRODE IN PURIFIED WATER

Storing the pH electrode in purified water (RO, DI, or distilled) will shorten the life of your pH electrode.

The reference cell has a high salt solution. Placing the probe in purified water will cause the salt to diffuse out and the water to go in. Storage solution is not only formulated to maintain the reference salt concentration but also has chemicals to keep bacteria and fungus from growing. If storage solution is not available then use pH 4 buffer.

 

[wineforfun]

I will get some storage solution but I was just looking at this manual online and it says bottle drinking water can be used?


http://www.milwaukeeinstruments.com/site/pdf/pH55-pH56_Starter_Manual.pdf

I have the same meter. I had read the same thing. I have kept mine in both the solution and bottled water, at different times. I will admit, I haven't used it for awhile.

 

[ibglowin]

You may be able to get by with regular drinking water as it has ions in it still whereas the other listed do not. Its the lack of ions that "strips" the probe to malfunction as it will all diffuse outward. If your having problems you need to pickup some cleaning solution. I bought mine from Hanna last Spring.

 

[geek]

Thanks.

I am trying to buy the cleaning solution in a small pack or bottle since I assume is not used that much, on the other hand the storage solution I find is like 230ml bottle which seems like too much....

 

[mikewatkins727]

Where is everyone getting pH meter solution from?
The cleaning and storage solution at Label Peelers is like 230ml and I'd like something smaller for the time being, especially the cleaning solution.

Don't see or can't find at MoreWine in smaller size.

MoreWine: MT614, 4 oz, 7.00 calibration solution (green)
MT612, oz, 4.00 calibration solution (pink)

 

[geek]

I ended up sending my daughter to the nearest local hbs and got a sachet of cleaning solution.
Followed instructions on the sachet and left ph meter for exactly 2 minutes and then rinsed with tap water.
Tried to re-calibrate again, the 7.01 passed ok no problem then it took a few seconds in the 4.01 until it read 'Ok' but then the reading went down to 3.97/3.98

I really wonder if the cleaning solution works well, I think my unit has some stain from red wine....

If it only calibrates off to 3.98, am I suppose to then remember to up the pH reading I get moving forward?
For example, my fermenting red wine batch from grapes measured at pH 3.42 last night, I assume that the pH is really 3.45 or so? (which is a GREAT number if it stays this way going to MLF).

 

[ibglowin]

Varis,

Let me see if I understand your "problem".

This is a $50 pH meter.

You cleaned the meter and re-calibrated it and it is still dropping from 4.01 to 3.98 or 0.03 pH units.

There is nothing wrong with the pH meter and that is completely within the "noise" of any pH meter especially a $50 pH meter!

Quit worrying. Go drink some wine!

I ended up sending my daughter to the nearest local hbs and got a sachet of cleaning solution.
Followed instructions on the sachet and left ph meter for exactly 2 minutes and then rinsed with tap water.
Tried to re-calibrate again, the 7.01 passed ok no problem then it took a few seconds in the 4.01 until it read 'Ok' but then the reading went down to 3.97/3.98

I really wonder if the cleaning solution works well, I think my unit has some stain from red wine....

If it only calibrates off to 3.98, am I suppose to then remember to up the pH reading I get moving forward?
For example, my fermenting red wine batch from grapes measured at pH 3.42 last night, I assume that the pH is really 3.45 or so? (which is a GREAT number if it stays this way going to MLF).

 

[geek]

So you don't worry about the difference ha.....

 

[ibglowin]

You should not be worrying about anything less than 0.1pH units on a $50 meter!

 

[BlueStimulator]

You should not be worrying about anything less than 0.1pH units on a $50 meter!

He be glowin and is one smart dude and uses all sorts of stuff like this in his real job in lost almost::::