Well, I finally bought a ph meter - a Milwaukee MW101 (newer version of SM101): http://www.milwaukeetesters.com/MW101.html
There’s quite a few on ebay right now for $77 (brand new).
Anyway, I know you are supposed to store the probe in special storage solution. What is the best way to do this? Do you actually disconnect the probe and store it in the bottle of solution or do you just put a bit of solution in the cap that covers the probe?
Thats the way I store mine!
Same here
I recently purchased the same meter. The probe ideally should be stored in the “storage solution” at all times. I use distilled water. I am planning to store the probe in a small water bottle with a hole and slot cut into the cap to accomodate the wire.
Here’s a video on calibration I got from the Milwaulee website…
I used to store my meter with just some liquid in the cap, but I’ve improved on that.
I took a White Labs yeast vial and drilled a hole in the cap that was sized closely to the pH probe diameter. I then took pH 4 calibration solution and dissolved pottasium chloride in it. I think the vial holds about 40 mL and I think I added about 4 g of KCl to that. It took several days for the chunks of KCl to dissolve, but it did dissolve fully. I hung the vial on the peg board on my wall and I just slip the meter in there. Works very well.
You probably have just about all the things you need to do this trick. You should have the pH 4 solution and you probably have a yeast vial. Getting KCl may be a little more difficult, but its a typical alternative used in water softeners. You literally need only a couple of chunks to supply the 4 g of KCl.
Great idea Martin!
That would mean that I’d have to buy White Labs yeast, though…
Not me…I have about 40 of those vials stored in a box in my brewery. 
I’ll bring one to San Diego if you want Denny. ;D
My pH56 manual (very similar to your pH55) says: “NEVER USE DISTILLED OR DEIONIZED WATER
FOR STORAGE PURPOSE.”
From the quick guide: “STORAGE OF THE PH55 – PH56:
Leave the protective cap off and put the unit back in a cup or jar that has 1” to 1.5” of either bottle drinking water, or 4.01 calibration solution, or MA9015 storage solution.”
From the less quick, quick guide: “After use always turn the meter OFF, rinse
the electrode with water to minimize contamination
and store it with a few drops of storage
(MA9015) or pH7 (M10007) solution in the
protective cap.”
Interesting. :-\ I’ll try contacting Milwaukee on this.
I’ll also note that bottled drinking water “can be” very similiar to distilled water.
Not a bad idea to contact them since their manuals vary a bit. I’m guessing they want some salts in the storage media, even if very small amounts. Let us know what they say.
Martin–I’m curious–why are you adding the 4 g of KCl to the pH 4.01 buffer solution? Being the water expert you are, I’m sure you have a very good reason.
That KCl addition is only to create the probe storage solution. Its not added to the 4 buffer that you’ll use to calibrate with.
As I understand it, the electrical bridge within the probe’s glass bulb is filled with a similar potassium infused solution and having a potassium saturated solution outside of the bulb places a positive osmotic stress on the bulb and keeps the pottassium in the bulb. For the same reason, that is why they say DO NOT store the probe in DI water since then there is a negative osmotic stress that actually draws the potassium out of the probe and destroys it.
So, if I’m understanding you correctly, to create the probe storage solution one adds 4 grams of KCL to about 40 ml of pH 4.01 buffer solution within a “repurposed” White Labs vial while the rest of the pH 4.01 buffer solution remains in a separate container for calibration purposes. Thanks for explaining the purpose for adding KCl.
You can also buy storage solution if you’re lazy:
Cool, thanks for all the replies. Storing the probe in a yeast vial is a great idea (I know I was saving those things for a reason).
I ordered some calibration and storage solution last weekend, hopefully it will arrive in time for Sunday’s brew session.
Well…I just got off the phone with Milwaukee about the probe storage solution question. You would never guess what they said.
The recommendation from Milwaukee is:
“The best way to store the probe is to get a small container and fill it with"regular tap water”, remove the cap and store the probe in the water."
Hard to believe…but true.
This makes things very easy. BTW…he also said to make sure you don’t use distilled or deionized water just regular tap water.
So, why does Milwaukee sell storage solution then?
Did you ask to speak to this guy’s manager? It is entirely possible that someone’s water is almost as soft as distilled water… how would they even know?
Good questions. Don’t shoot the messenger.
Just relaying info. that a representative from Milwaukee has conveyed. Maybe they want to sell more probes…but my guess is that it is okay to store them in tap water profiles wide ranging. I would only encourage you to contact them yourself to inquire further. If you do, please let us know what you find out.
Thanks for calling… I already own the storage solution, so I’m just going to be lazy and stick with it.