Help chosing a pH meter?

[metic]

I'm looking for a bit of help in chosing a pH meter. I've done some research in this forum and more widely on the web, but I'm having trouble settling on a particular model. I would mainly be using the meter for testing mash pH, along with the pH of sour beers, but I might also use it to check pH in other vegetable ferments too.

I'm currently chosing between the Milwaukee MW102 and the Hach Pocket Pro+. Both seem to have the specs I need, and both are in my price range (although the Hach will be a bit more expensive with shipping etc.). But it also seems that people have had trouble with both models, so I'm not which to go with. Any guidance here would be appreciated. Thanks!

 

[ajdelange]

Some number of people are going to have trouble with any pH meter (or other piece of equipment). One guy had a bad electrode from Hach and another broke his (physically). Hach replaced both quickly at no charge.

I don't remember particular problems with the MW102 but I am sure there have been similar events with it. The one that people seem to have trouble with is the MW101.

There are several sets of stability data on the Hach (one in a current thread). I haven't seen any on the MW102.

If the MW102 is as stable as the Hach then either should do and it comes down, in part, whether you want pen style or benchtop style meter. You can, with the benchtop, attach any electrode with a BNC connector. You can't do that with the Hach.

I chose the Hach mainly to see if it as good as their other gear (i.e. rugged). It appears to be. You won't find Hach in many research laboratories but you will find them in many a water treatment plant and they are starting to cosy up to brewers.

 

[metic]

Thanks, that is helpful. I am leaning towards the Hach: I'd rather pay a little bit more up front for something that will be reliable in the long run. Am I right in thinking that I should also buy buffer powder and storage solution? Are the products I've linked to the right ones? Thanks again.

 

[ajdelange]

Yes, you will definitely need the buffers. You will also need some containers to put the buffers in. Hach ships three of these: http://www.hach.com/sample-container-120ml-high-pf/product?id=7640237101&callback=qs with their more expensive meters and they work fine. Get one for each of the 4.0 and 7 buffers (you don't need 10 for most brewing applications) and one to save storage solution (see below).

The storage solution is under debate. The manual says store it dry. As no one could believe that several people have called them and they seem to be leaning towards storing it in solution now. In most cases a pH electrode is in a narrow tube with a small fitting cap with a sponge and if it takes more than 2 mL of storage solution to fill it I'd be surprised. With this thing, though, the cap is the sample cup and it takes more than a few mL to fill it. Even so a few (5?) mL should be enough to cover the bulb. In any case 50 ml isn't going to last long. Each time you use the meter you will have to throw the storage solution away (unless you want to transfer it to another container). I'd look at http://www.hach.com/ph-electrode-storage-solution-500-ml/product?id=7640206852&callback=qs - 10 times the solution for 3X the $. Still an outrage. I'd be tempted to go shopping for some KCl and make up some 3M solution myself.

 

[metic]

OK thanks. Is there any reason to favour storage solution from Hach? Could I use this instead, for instance? What about buffers? It looks like they are also cheaper on Amazon.

 

[NeoBrew]

It looks like the Milwaukee has a resolution of .02 while the Hatch is .01. Seems like more accurate for the same price is better.

Why aren't you considering the Hanna prep5? That seems to be a very popular one for slightly less money. I'm thinking of buying a meter soon too. I'll be watching this thread.


Sent from my iPad using Home Brew

 

[metic]

The Hach Pocket Pro+ (9532000) has .02 resolution. The cheaper Pocket Pro (9531000) has .01 resolution.

I ruled out the Hanna pHep 5 based on ajdelange's comments about its automatic calibration in this thread, but maybe I was too hasty.

 

[ajdelange]

It's actually the other way round. The + is more expensive and has the better accuracy/resolution. Well worth it.

Yes, you can buy someone else's buffers and storage solution.

One of the things you really need to look for in these inexpensive meters is stability. The Hach is very stable. The pHep5 is also stable but there is a big difference. When one calibrates the meter the Hach lets you decide when to accept the buffer reading. The Hanna decides for you and typically grabs the reading before it is really stable. Thus you cannot calibrate it as accurately as you can the Hach.