Milwaukee PH55 meter information/update

My meter had been acting unusual and then it was acting normally but the calibration routine kept showing me “WRNG” (wrong?) and I didn’t like not knowing why. I remembered that during some recent troubleshooting I sent Milwaukee an email asking for help regarding the “WRNG” message and they never returned it. I’m thinking that my meter has been behaving itself but I want to know about this message and also if my meter is just whack and needs replacement. I called them today and got ahold of Jason in support. I explained my situation and he suggested that I store the meter in some white distilled vinegar overnight, then rinse it and try to recalibrate it. He said that sometimes some type of dirt or schputz can get stuck on the probe and cause problems. Remember that my meter is relatively new and has been stored in storage solution (most of the time) or drinking water (which they say is acceptable) part of the time. So I got some white distilled vinegar (he was very specific) and place my meter in there. I came back about 5 minutes later and swirled it a little and I also turned it on. Apparently the pH of my vinegar is 2.1. But I noticed small flakes of schputz and film coming off of the probe. Hmm, appears there was something dirty on the probe. I left it there another 30 minutes or so, rinsed it off and calibrated it. It calibrated without giving me the WRNG message. It went through the calibration as it should. Very interesting. It’s back in the vinegar now and I’ll let it soak overnight as he suggested and then check it again tomorrow. Thought I would share because it could have an impact on how the meter performs… or not.

I have seen many people online in both beer & gardening forums complaining that this model acts this way. Not sure how many could benefit from this but it could be helpful.

According to the manual, the “WRNG” message indicates an invalid buffer used during calibration.

Check to ensure that you are mixing your 4 and 7 buffer solutions properly or using pre-mixed solutions.

http://www.milwaukeetesters.com/pdf/pH56_Manual.pdf

I had the same problem too, going to give that a try. Just went back to strips and have been getting consistent results from Bru’n Water so I haven’t been worrying about it.

[quote=“GeneticBrew”]According to the manual, the “WRNG” message indicates an invalid buffer used during calibration.

Check to ensure that you are mixing your 4 and 7 buffer solutions properly or using pre-mixed solutions.

http://www.milwaukeetesters.com/pdf/pH56_Manual.pdf
[/quote]
Brand new, premixed solutions poured into a clean glass just seconds before the calibration.

[quote=“Ken Lenard”][quote=“GeneticBrew”]According to the manual, the “WRNG” message indicates an invalid buffer used during calibration.

Check to ensure that you are mixing your 4 and 7 buffer solutions properly or using pre-mixed solutions.

http://www.milwaukeetesters.com/pdf/pH56_Manual.pdf
[/quote]
Brand new, premixed solutions poured into a clean glass just seconds before the calibration.[/quote]

You’ve tried cleaning, but what about replacing your electrode.

Also, check how long it takes for the calibration readings to stabilize.

If they never stabilize that could indicate a problem.

I’ve had good luck with the HM Digital PH-200 and Milwaukee MW101.

PH Meters are finicky devices and must be kept clean, stored properly and calibrated, in order to work well. These things are sometimes forgotten while brewing.

This is what has been happening to me (using an MW101). My probe is a couple of years old, so maybe it is time for a replacement.

I’ll probably put it off for a while as I’ve been having such good results with Martin and Kai’s spreadsheets and the Colorphast strips (applying the .3 correction factor).

Well, this meter is about 6 months old so if the probe needs replacing then I’m either back to strips or getting another meter. I store the meter in storage solution and calibrate it when it doesn’t read the 4.0 or 7.0 solutions properly. It does take awhile to stabilize but it’s a slow-constant thing. If I put it into the 4.0 and it reads 4.0 and then put it into the 7.0, it will creep slowly towards 7.0 and eventually get there but it could easily be 5 minutes.

I have a pH56 that I got around the same time as KL got his and it is doing the exact same thing, I’ll have to give the vinegar a go. It started doing it after around 10 uses, everywhere I read said to replace the probe, but damn, they’re about half the price of a new meter.

Have you ever calibrated your meter in the 4.01 solution, then the 7.01 solution, and then stuck it back in 4.01 solution to see if it still reads 4.01?

This is very frustrating to hear. I find a lot of people online (some brewers, some ‘gardeners’) who have complained about this/these meter(s). Very, very frustrating because my guess is that the technology is not far away where an entry-level, affordable meter comes out that is less of a hassle. It’s quite expensive to care for these meters. The storage and calibration solutions are not cheap and they don’t last long either. I feel like I’m treating this thing properly but all I have to do is fart in its vicinity and it’s out of whack again. :x

Have you ever calibrated your meter in the 4.01 solution, then the 7.01 solution, and then stuck it back in 4.01 solution to see if it still reads 4.01?[/quote]
I think you just broke my brain. The only calibration procedure I have seen for this meter is to start with the 7.0, then the meter registers it and actually asks for the 4.0… move the meter to the 4.0 and wait. That’s what I do. When it’s done, I walk around and measure everything… the 4.0, the 7.0, my tap water, the beer I’m drinking, vinegar, back to the 4.0, etc.

Sorry, I only ask because I’ve had it happen to me (where I’ve calibrated the meter at 4, then at 7, then stuck it back in the 4 only to have it read 3.7 or some such) and found it extremely annoying. Like I posted before though, my probe is a few years old and possibly in need of replacing.

I have the same issues with the PH55 and PH56 meters I have bought. The probes even stored correctly seem to last about one year. Thats fine in a lab that uses it every day but a little to much for a brewer that brews maybe once a month.
I though that once I got my methods recorded the PH would be the same every brew. My last brew that I have made many times was loaded with tannins and I batch sparge.
Come to find out my R.O. water had changed and had a PH of 8.
I now have purchased a MW101 bench type meter. I have yet to use it but to calibrate you turn two pots one for 4.01 and the other for 7.01 till the scale reads the value of the calibration buffer. A brewer told me he now never gets errors with his.

[quote=“DUNNGOOD”]I have the same issues with the PH55 and PH56 meters I have bought. The probes even stored correctly seem to last about one year. Thats fine in a lab that uses it every day but a little to much for a brewer that brews maybe once a month.
I though that once I got my methods recorded the PH would be the same every brew. My last brew that I have made many times was loaded with tannins and I batch sparge.
Come to find out my R.O. water had changed and had a PH of 8.
I now have purchased a MW101 bench type meter. I have yet to use it but to calibrate you turn two pots one for 4.01 and the other for 7.01 till the scale reads the value of the calibration buffer. A brewer told me he now never gets errors with his.[/quote]
Another brewer I know uses the MW101 and says it’s very good as well. I’m going to go along with this one for a little longer and if all signs point to ‘bad meter’, I’m chucking it and getting the MW101 instead. It would be a $50 lesson but worth it in the long run, I suppose.

I have the PH56. I experienced the WRNG problem during calibration when it was fresh out of the box. I had followed instructions to activate the probe. I still used it for a while, because it seemed to calibrate fine in spite of the warning. I got pretty annoyed with the error message, though, so I decided to contact support.

The support guy had me go through the same procedure: soak in distilled vinegar for several hours, because he thought the probe may be dirty. It still didn’t read right, so they sent me a replacement probe. Even with a new probe, it produced the WRNG message. I sent the unit to them for testing. I never heard back from them, but I got a new, sealed replacement meter in the mail not long after.

That was last summer. The new one calibrates perfectly every time, but it is starting to take longer for the reading to settle. I am following the support guy’s advice to soak the meter in vinegar for a few minutes before storing it after a brew session. Although the user guide says that “drinking water” can be used, I am starting to think it does not supply the necessary ions to maintain the electrode. So I picked up a 500ml bottle of storage solution on Amazon pretty cheap and will use that when I install a new electrode (which I also got on Amazon for ~$25 shipped).

[quote=“DUNNGOOD”] … My last brew that I have made many times was loaded with tannins and I batch sparge.
Come to find out my R.O. water had changed and had a PH of 8.

…[/quote]
From what I understand, the pH of your RO water means almost nothing. It’s the buffering that is important, and RO with almost no minerals has very little buffering. The pH of the water will be pulled by all the ‘stuff’ in your grain bill. It’s the mineral content of the water that interacts with the grain to reach a certain pH level, the pH of that water itself isn’t that significant, especially in RO water.

Think of pH as ‘temperature’ versus ‘heat content’. One drop of water added to 10# of grain will not change the temperature meaningfully, even if that water is hot @ 212F or cold @ 32F. A single drop just does not have enough heat content, even though it’s temperature is high.

-kenc

I know that the buffering effect of Batch Sparging helps not to extract tannins in the sparge but I think it has limits. With ph being a big factor in extracting tannins in the sparge I would think sparge water with a ph of 8 can pull tannins even with Batch Sparging. Here are some replies I recived from another forum.

Denny.
I think it’s entirely possible with water like that. With less extreme water, tannin extraction with batch sparging isn’t usually a problem. Although I haven’t personally tested it, I’ve heard reports of batch spargers with really bad water having pH issues during the sparge.

Mabrungard.

For Sure! Water with elevated alkalinity is almost guaranteed to pull tannins and silicates out of the grist. A simple acidification of that water would solve the alkalinity, but the high sodium won’t be solved by anything but RO treatment. Looks like you need to find another machine. As I’ve recommended before, anyone using a commercial RO machine or their own, should have a TDS meter with them to check that the RO water really has very low TDS. If it doesn’t, something is wrong. TDS meters are cheap and reliable…much less expensive than a screwed up batch of beer.

I hope it is ok to repost but I think this is great infro.

I think what those refs are saying is it is the mineral content in that water that is affecting the sparge pH, not the water pH by itself.

Maybe they can chime in and verify that or set me straight, they are far more expert than I am. But I think you are misinterpreting or reading in a little to what they said.

-kenc

I am certainly not an expert either. I now understand what you are saying and I agree. My problem was what I thought was r.o. turned out to be very hard water being sold as r.o.
It had a TDS of 353 and Hco3 of 244.
This is a very interesting point and I am interested in learning more.

Some of these posts have convinced me to buy a TDS meter to verify my home RO is working properly. I’ve done some very crude tests, just evaporating measured volume samples pre-and-post-RO and I can see a difference in deposits left behind (almost nothing in the RO), and some crude electrical measurement that showed a > 10x difference in conductivity as expected, so I think I’m OK.

Does anyone have a cheap TDS meter they recommend? I prefer things that take AAA or AA batteries (I always have a stock of those) over coin cells, if anyone knows of any like that.

-kenc

I like the meters from HM Digital. But it’s a fairly simple instrument that does not have a lot that can go wrong. It is essentially a sensitive Ohm meter with probes that are precisely spaced. Another consideration is that you are primarily looking at the relative difference in successive readings as opposed to the actual values. If a reading for a water changes by 50 ppm, that is meaningful. It won’t really matter that the meter reads 100 ppm and the water actually has 110 ppm in it.