pH Meter - MW102 or Hach Pocket Pro+

[CyclingCraig]

So after tons and tons of reading here (Much thanks to AJ and Martin for their work on contributions)

I am still not sure which meter I should get:
The MW102: Link to Amazon

Or

Hach Pocket Pro+:
Link to Hach site

It seems both have had QC problems, and lately people have been seeing stability issues with the Hach.

I know Martin uses the MW101, but haven't seen much reviews on the MW102?

So If YOU were going to buy either of these, which you get?
(ps also planning on getting the buffer calibration solution pillows from Hach for the required calibrations).

Thanks
-Craig

 

[ajdelange]

I hadn't seen stability problems reported on either the MW102 or the Hach (other than the one's that came with a bad probe the replacement of which solved the problem).

Any pH meter that sells for ca $100 is a toy. So both these meters are toys. Why would I buy a toy from Hach and not Milwaukee? Because I have bought pH meters (several) from Hach that are not toys and I have bought several other instruments and many a test kit from them that are not toys either. IOW I know the company and I know they aren't lkely to jeopardize their reputation by selling a pH meter that comes to be considered a toy in the market. This is, I assume, why they are bending over backwards to replace meters and electrodes that show the slightest problem. One guy here reported an exception to this but was later satisfied. He thinks his tech had a fight with his girlfriend the day he called or some such.

I don't have any equivalent information about Milwaukee. I know they do make some 'professional' instruments but they seem more aimed at the education market (Hach is aimed at the water treatment market but did exhibit at the last MBAA conference).

I don't know if that helps. I don't think you'll find a lot of difference in performance when it comes right down to it. The MW101 has (had) a terrible reputation (it was analog) which, fortunately, doesn't seem to be shared by the (digital) 102. The Milwaukee units do have a detachable electrode so that you could, presumably, buy a high quality electrode (costs more than the meter) from Hach (or anyone else) if you wanted to but they don't, strangely, seem to have a mV mode (or at least not mentioned in their spec sheet) but then again neither does the Hach (mV mode is useful if you want to do your own ATC/Cal which is very useful when the meter decides the electrode is worn out and won't cal for you).

 

[mabrungard]

AJ, I'm curious where you are reading that the MW 101 has a terrible reputation? I just Googled reviews for that meter and the only place I can find reviews is Amazon. I see 3 reviews out of the 9 total that gave it a bad review and in each case, it was apparent that they were faulty from the start. There was none of that...started out working well for a few months and then crapped out. I would much rather have a unit fail early than later since I can more easily obtain a replacement.

The other reviews are glowing. My review is also glowing.

 

[Hermit]

I have the 102. It seems to work though I think it is a little slow but I have no other frame of reference. The hourglass that indicates a stable reading seems to be a tad on the optimistic side but I've learned to work around that by basically ignoring it. You can also ignore it during calibration which is the key to my getting used to it I think.

 

[ajdelange]

AJ, I'm curious where you are reading that the MW 101 has a terrible reputation?

Last time I researched it (months or perhaps even over a year ago) the reviews were at least 50% negative (not only Amazon) and there were additional terrible reviews here on HBT. I think I remember asking, the last time this came up, 'would you want to take a 50% chance on getting a bad meter? I can allow that they may have fixed some things since then. Their stuff is apparently now made in Italy instead of Romania (not that this would or would not necessarily make a difference). Probably the biggest problem with the 101 is that it is an analogue design whereas all the others are digital. This is 2014. I know there are those who still swear that vinyl sounds better than CD's but the advantages of digital implementation are manifold and apparent to most (well most engineers anyway).

 

[ajdelange]

I have the 102. It seems to work though I think it is a little slow but I have no other frame of reference. The hourglass that indicates a stable reading seems to be a tad on the optimistic side but I've learned to work around that by basically ignoring it.

Like many things coming to equilibrium the change is great at first and then becomes gradual. You should have a useable pH reading within 30 seconds but it is better if you can wait two minutes.

You can also ignore it during calibration which is the key to my getting used to it I think.

This is critical. You should not buy a meter that doesn't allow this. The lack of ability to do this is what kills the Hanna pHEP meters which would otherwise be pretty good meters.

 

[CyclingCraig]

Thanks everyone for your help and input.

This leads me to a follow up question. With all the talk about the stability of a pH meter, is the stability a function of the physical probe itself (The part with the glass bulb, junctions and gel) or does the electronic parts that read the voltage play a part in the stability?

If it's just the probe part, and I end up with the MW102 and I find I have stability issues or my probe wears out, can I just replace the "BNC Probe" with a better one and achieve better performance?

Maybe something like this: BRS Lab grade probe

It claims to use "Pelon strips" as the junction material instead of the ceramic ones in standard probes.

Thanks
-Craig

 

[ajdelange]

This leads me to a follow up question. With all the talk about the stability of a pH meter, is the stability a function of the physical probe itself (The part with the glass bulb, junctions and gel) or does the electronic parts that read the voltage play a part in the stability?

I believe it is the electrodes based on the assumption that it would be pretty hard to screw up the design of modern digital electronics to the point where they exhibit the kind of drift we see with a pH meter. To test one could put a say 1 MΩ resistor across the input. The meter should read a pH near 7 (depending on its last calibration) which should be absolutely stable.

If it's just the probe part, and I end up with the MW102 and I find I have stability issues or my probe wears out, can I just replace the "BNC Probe" with a better one and achieve better performance?

Yes, you can replace it with any electrode you like as long as it has a BNC connector.

Maybe something like this: BRS Lab grade probe

I don't know about this particular electrode but at the price point am not sure it is any better than the one that comes with the meter. A 'good' electrode is usually a $200 or up investment.

It claims to use "Pelon strips" as the junction material instead of the ceramic ones in standard probes.

I assume that's 'Pellon' which is a bundle of fibers IOW what I call a 'rag junction'. These have become quite popular in low $ electrodes and they seem to function well. The junction in the electrode that comes with the meter may well be Pellon too.

 

[Roundhouse]

I've got the 102. It can be a bit on the slow side but has generally seemed to work well. It may not be the best in the world when compared to true lab grade meters but for my needs at the home level I'm not going to complain. I'm not sure what benefit I'd get from replacing it.

 

[ajdelange]

You'd have a better meter but do you need a better meter? Do you use non-NIST buffers? Do you need each reading logged with date of calibration, slope and offset recorded? Do you need the meter to make measurements automatically or in response to computer command? Do you need to simultaneously record pH and ORP or conductivity or DO? If you answer all of those questions in the negative and your meter will pass the cal and stability checks you don't need a better meter.

 

[Spartan1979]

I've been using the MW101 for 2-1/2 years now and it's worked fine. When I recalibrate it, it's only off by a couple of hundreths. It's a little slow, but I'm not in a great hurry anyway. I'm still on the original probe.

 

[revansCAAD8]

AJ, I'm curious where you are reading that the MW 101 has a terrible reputation? I just Googled reviews for that meter and the only place I can find reviews is Amazon. I see 3 reviews out of the 9 total that gave it a bad review and in each case, it was apparent that they were faulty from the start. There was none of that...started out working well for a few months and then crapped out. I would much rather have a unit fail early than later since I can more easily obtain a replacement.

The other reviews are glowing. My review is also glowing.

Amen, we have been happy with our MW101. Got a great deal on it too and bought a spare electrode just in case.

 

[jscherff]

Any pH meter that sells for $100 is a toy. So both these meters are toys.

AJ, at what price point does one cross beyond the "toy" threshold for pH meters? Do you have any specific recommendations? Would you mind sharing what make/model you use and/or prefer? I have read (ravenously) your advice throughout this site, and it is abundantly clear that you believe a good pH meter is a prudent investment.

 

[jbaysurfer]

I believe it is the electrodes based on the assumption that it would be pretty hard to screw up the design of modern digital electronics to the point where they exhibit the kind of drift we see with a pH meter. To test one could put a say 1 MΩ resistor across the input. The meter should read a pH near 7 (depending on its last calibration) which should be absolutely stable.



Yes, you can replace it with any electrode you like as long as it has a BNC connector.




I don't know about this particular electrode but at the price point am not sure it is any better than the one that comes with the meter. A 'good' electrode is usually a $200 or up investment.



I assume that's 'Pellon' which is a bundle of fibers IOW what I call a 'rag junction'. These have become quite popular in low $ electrodes and they seem to function well. The junction in the electrode that comes with the meter may well be Pellon too.

So hypothetically, if I were looking to purchase one of these "good" electrodes, do you have any suggestions?

Edit: Wow Jscherff...was that the phone app triple posting?

 

[Hermit]

I have the Milwaukee 102. Is it my dream meter? No. Could I justify spending more? Probably not. I'm quite happy with my last bottled beer. It is a blond. I have to set it down and walk away from it to keep from downing it in under 5 minutes. My water is 'challenging' and even defies RO treatment because of the high pH. Even had I bought RO water at the local store I would have just been getting the same results and not knowing why. AJ's advice to MEASURE was the only way I would have ever known what was going on. I even measured 40+ppm in the "distilled" water I bought from one retailer. For me, something was way better than nothing.

 

[ajdelange]

AJ, at what price point does one cross beyond the "toy" threshold for pH meters?

That's not an easy question. Obviously I can sell you an MW101 for $300 (if you are foolish enough to pay it) but that doesn't make the meter a professional meter. After years of buying instrumentation of various types for a diversity of purposes one develops a sense of where the thresholds lie. Specs alone are no longer adequate as the toys have specs identical to the industrial quality meters. What they don't tell you is what their test conditions are when they measure '0.01 accuracy'. I take that to mean that if you do a fresh cal and then return the probe to one of the buffers and take a series of measurements over some reasonable period of time such as half an out that the measurements will exhibit 1 sigma dispersion of 0.01 about the buffer's published value at the temperature which will have been held constant for calibration and the test. I have, in all the specs I have ever looked at, only seen it confirmed once that this is indeed what the accuracy spec for that meter (the Hach Pocket Pro +) was based on. It is interesting that Hach does not give that assurance in the specs for any of their other meters. Think about the same question applied to toy microscopes or telescopes.

One might hope to gain some insight by looking at who sells the meter to whom. If the meter is found in the Cole Parmer catalogue, for example, one might expect that it is not a toy. But they sell lots of the pocket tester type meters (which I have been calling toys) as there are industrial applications for which they are adequate. You can look at the brands you find listed in such a catalogue: Hach, Oakton, Thermo/Orion, YSI and get an idea from that as to which are the 'better' brands. Another thought is to keep your eyes open whenever you are in a brewery to see whose meters they are using.

The other problem with price is that once the electronics get to a certain level (i.e. digital with ATC) marginal price often depends on features such as multiple channels, ability to accept other sensors (ORP, ISE, conductivity, DO), computer interface...) that you may not need. Paying $1000 for a meter that does some of these things is a waste of money if you don't need them.

It gets even harder with electrodes. You can look at electrode descriptions and find things like 'double junction', 'renewable junction', 'refillable' etc and conclude, that since these features add cost, that they must be worth having. And indeed they are. Refillability, for example, is worthless to you if you use the electrode so seldom that you wouldn't consume the gel in a non-refillable electrode. Ten years ago I would absolutely recommend renewable, double junction electrodes for brewing because of protein. With modern more conventional junctions neither of these seem to be so important. We note with interest that electrode life is never specified.

Do you have any specific recommendations?

This is tough for some of the reasons set out above. I can't say whether a mid priced ($400) YSI meter is a good buy or not as I have never had my hands on one (but I have seen them in breweries). I'm not Consumers Reports for pH meters. I can make comments based on what I have seen here and else where in Reviews but even that may not be up to date and the MW101 owners get upset. I can also comment, again with respect to that meter, that I would be remiss in recommending an analog meter when the same company makes a digital meter for nearly the same price.

Would you mind sharing what make/model you use and/or prefer?

I use an Hach HQ40d meter in the brewery and a Hach Sension benchtop in the lab.
I also have a little box that plugs into my iPhone that I bought from Hach though it is made by someone else.

I would not recommend any of these to anyone here. Not because they aren't good meters but because you would be paying for features you don't use. When I do stuff like run titration curves on malts that are going to be published in Palmer/Kaminsky's book the data has to be as accurate as I can get it. The lab meter I use takes a reading every 10 seconds or so and those readings go straight to a computer where they are ghraphically displayed so I can clearly see when equilibria are reached, average readings, do calibrations by moving cursors around on the screen etc. If you need to do that sort of thing then I enthusiastically recommend these meters. They also use an indestructible, it seems, renewable junction electrode that just won't die.

I have read (ravenously) your advice throughout this site, and it is abundantly clear that you believe a good pH meter is a prudent investment.

It is but the question of what to buy is almost as broad as 'What car should I buy?'

 

[jscherff]

All, I sincerely apologize for the multiple posts. Geez. The iPhone app for this site kept saying the post failed and to wait 30 seconds before trying again. I kept trying (obviously) but finally gave up. I'll try to clean it up shortly.

UPDATE: looks like I don't have the ability to delete my duplicate posts. Maybe a moderator can help out. Again, sorry for the clutter.

 

[jscherff]

AJ, thank you for the thorough response. It makes sense and I understand that it is not a simple question to answer. I have the Milwaukee MW102 and have been quite surprised at the delta between the pH predicted on the spreadsheets and at Brewer's Friend and the actual mash pH reported by my meter (the meter is often 0.2 and occasionally 0.3 lower than the predicted pH). I also start with RO water (for most beers, imperial stouts being the main exception) and build up the water profile from there, so there should be no variability introduced by the source water. I thought there might be an issue with the meter, my technique, my calibration, or some combination of those things, but I've gathered from some of your other posts that this may actually be due to my timing. I was unaware that there is an initial drop in pH followed by a gradual rise that (if I understand correctly) levels off around 15-20 minutes into the mash. I've always taken my reading about 5 minutes after dough-in. My concern about taking readings later and making adjustments later was that the enzymes might have been denatured at that point if the pH is too far off. I'll adjust my sample time for my next batch and see if that makes a difference.

 

[Hermit]

Remember, the calculators are simply estimates. Malt varies. Check your meter in the buffers after the reading. If they are close then it may be the malt you are buying isn't the same as modeled. Not a big deal. If you are consistently lower it could be the base malt if you always use the same. Not a big deal if the prediction is off and repeatable though. Just adjust, and if your meter shows it is holding calibration, trust it.

 

[ajdelange]

I have the Milwaukee MW102 and have been quite surprised at the delta between the pH predicted on the spreadsheets and at Brewer's Friend and the actual mash pH reported by my meter (the meter is often 0.2 and occasionally 0.3 lower than the predicted pH).

It's as likely to be a problem with the calculator as the meter. Check the meter using the protocol at https://www.homebrewtalk.com/f128/ph-meter-calibration-302256/ so that you are confident in it.

I thought there might be an issue with the meter, my technique, my calibration, or some combination of those things, but I've gathered from some of your other posts that this may actually be due to my timing.

That's what the stability and cal check tests are for.

I was unaware that there is an initial drop in pH followed by a gradual rise that (if I understand correctly) levels off around 15-20 minutes into the mash. I've always taken my reading about 5 minutes after dough-in.

The pH can exhibit various behaviors within the first 20 minutes after mashing but should be well settled by then. Most of the change occurs within the first 5 minutes.

My concern about taking readings later and making adjustments later was that the enzymes might have been denatured at that point if the pH is too far off. I'll adjust my sample time for my next batch and see if that makes a difference.

I strongly encourage people to make a small test mash with a new recipe or while coming up to speed on these techniques.

 

[CyclingCraig]

Thanks everyone for your help and useful responses.

I am leaning towards the MW102, I like the BNC probe option and working with a pen type seems a slightest bit (I mean really small)of an inconvenience to me. I think I rather place the probes in the sample and have the meter sitting on the table and not have to hold onto things.

Once I get the meter I will be sure to do a stability check and post so others can benefit from my findings.

But now I have a dilemma. I would like to use the Hach pH Buffer calibration "Pillows": Hach pH 7.00 calibration

But the Mw102 has a calibration point of 7.01 ?? and the Milwaukee solution is stated at 7.01?

It seems "Most" meters calibrate with 7.01, but some with 7.00... but all use 4.01 and & 10.01.

Since the meter is only accurate to .02, can I use the 7.00 to calibrate my MW102 ?

Thanks again all.

 

[Hermit]

But now I have a dilemma. I would like to use the Hach pH Buffer calibration "Pillows": Hach pH 7.00 calibration

But the Mw102 has a calibration point of 7.01 ?? and the Milwaukee solution is stated at 7.01?

The "pillows" state they are +/-.02 anyhow. Milwaukee's buffers claim +/- .01.

 

[ajdelange]

I am leaning towards the MW102, I like the BNC probe option and working with a pen type seems a slightest bit (I mean really small)of an inconvenience to me. I think I rather place the probes in the sample and have the meter sitting on the table and not have to hold onto things.

Note that the Hach meter is a little different than most of the pen types. In Hach unit the sample (and the buffers) go into the cap which seals to the body. The bad news is that you cannot poke the electrode into a buffer container. I suppose the good news is that you are forced to use fresh buffer each time (unless you are really stubborn and want to pour back from the cap into the buffer container which I wouldn't recommend. While waiting for stabilization you can set it in a coffee mug or stand it on the cap.

The more conventional electrode can be poke in almost anywhere. Some have complained of the necessity to have two probes with the 102 because of its ATC capability. If you come to feel strongly about that then you can always buy a new electrode from another manufacturer with the RTD built in as long as it has separate BNC and RTD connectors. You should check that the 102 accepts a standard RTD before you do this.

But now I have a dilemma. I would like to use the Hach pH Buffer calibration "Pillows": Hach pH 7.00 calibration

Not a problem. Both are going to be NIST traceable 'technical' buffers.

But the Mw102 has a calibration point of 7.01 ?? and the Milwaukee solution is stated at 7.01?

It seems "Most" meters calibrate with 7.01, but some with 7.00... but all use 4.01 and & 10.01.

The buffer value depends on temperature with a known dependence (which is in the pH Meter Calibration sticky. Whether the manufacturer calls it 7.01 or 7 strictly speaking depends on the temperature. Often the package will say something like " Buffer Solution 7.00 ± 0.02 @ 25 °C"

Since the meter is only accurate to .02, can I use the 7.00 to calibrate my MW102 ?

Yes. Several factors determine the accuracy of a meter. Putting electrode drift aside for a moment if the meter can measure voltage to ± 0.1 mV ( 1 sigma) and temperature to ±0.5 °C then it is capable of measuring pH to a wee bit better than 0.02 pH in the region in which we usually measure mash pH if the buffers are accurate to ±0.02 pH. The buffers are the determining factor here (assuming that the electrode's isoelectric pH is exactly 7 or that buffers and samples are all at the same temperature) and that is as it should be. We want the electronics contribution to the error budget to be unappreciable compared to the reference standards' contributions. This is why we study the meter's voltage and temperature measurement accuracies when looking at more expensive meters.

You can buy buffers specified at ±0.01. They are more expensive, of course, and won't get your accuracy down to a wee bit better than 0.01 because temperature and voltage reading errors do have some effect.

 

[CyclingCraig]

Hey all

Thanks again for all the input. I ended up with the Milwaukee MW102 and it was just delivered today.

I figured I would do an unboxing video if anyone would find it useful.

I will follow up with a stability test result. One question I have about the stability test is, in between measurements do I keep the probe in the pH 4 buffer the whole time, or do I take a reading, rinse(DI Water) and return to storage solution, then when time comes for next reading, rinse, take reading and repeat?

Here is my lame video (First attempt at an unboxing video):

 

[ajdelange]

Easiest to just leave it in the buffer.

 

[CyclingCraig]

Some initial thoughts on the MW102.

I got to brew on Saturday and it was my first real use of the meter. I am very happy to report that it is AWSEOME having a nice pH meter!! (Was using the toy pH600 before I got this one)

I was able to run a initial calibration on Friday night about 9:30 PM with pH 7.01 and pH 4.01 with the meter. Very simple operation and went fine.

The next morning I started my brew day. I use Bru'n Water for my water adjustment estimations (Sorry A.J. I didn't have time to do a test mash, but I hope to try that for the next brew day). I am also brewing with straight RO/DI water from my new RO/DI system and building my water from scratch. All I have to say is: Martin.. that spread sheet is awesome!.. it predicted my estimated mash pH at exactly 5.40

Here are the actual mash results:
pH @ 10 minutes into the mash: 5.40 @ 73.6F
pH @ 20 minutes into the mash: 5.37 @ 72.1F

In addition, I forgot to check the calibration at the beginning of the brew day, so right after the 10 minute check, I check the meter against the 4.01 buffer and it was right on the money at 4.01 without the need to re-calibrate !

So... almost 12 hours after calibration is was still reading 4.01 in the buffer! I would say that is pretty stable!

I still plan to run a true stability check as outlined in the calibration sticky and report back on the results, I just didn't have time before this brew day.

To sum it up, I am VERY VERY happy with my MW102 (Sample size of one use so far :cross: )

 

[ajdelange]

.. it predicted my estimated mash pH at 4.00.

I don't think that's what you meant to type.

 

[CyclingCraig]

I don't think that's what you meant to type.

AHHHHHH RATS!!.. You are correct, I will fix the post

Should be 5.40

 

[funnelweb]

For those with limit funds there's also this solution: http://www.ebay.com/itm/Digital-Poc...702320?pt=US_Garden_Tools&hash=item2ed5659e70

Works perfectly within tolerance

BR Folke

 

[ajdelange]

Just send the $7 to me and I will guess the pH with about the same accuracy as this meter.

Remarkable advances is what you can get for $100 have taken place in the field of pH measurement but there are limits. These guys only advertise accuracy of ±0.2 (which makes this pretty useless for brewing), its an analog meter, it has no ATC and apparently uses 1 point calibration.

"The bitterness of poor quality remains long after the sweetness of low price is forgotten."