want a decent ph meter that doesn't cost too much

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ph0ngwh0ng

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Hey!

I'm now at the point where I need to check my pH. I would like to do so without paying big bucks, though. Any one has links to sites selling DECENT, FUNCTIONAL pH meters?

Thanks in advance!
 
For $32 that Hanna meter is a pretty good deal!

I wanted a hand-held model with separate replaceable temp and ph probes so I went with the Milwaukee MW102 which can be had for $100. It is slightly more accurate than the Hanna meter linked to above but the big selling point is that the probes are replaceable when they die. With the integrated meters you just have to replace them when they die / dry out for too long.

Having said all that... If I could do it again, I'd probably just get the Hanna meter for $32 BECAUSE newer generation meters always seem to get faster and faster at taking readings and even though Milwaukee advertises the new MW102 as faster than the previous model, it's still not remotely fast enough for me. -I'd probably prefer to have my meter die ever 2 years or so so I could replace it with a newer model every couple of years.

I feel like I'm stuck with the MW102 forever now as I opted to pay extra for the replaceable probes. (If I ever found a great deal on a SUPER accurate and much cooler bench-top meter, I'd replace it, though.)
http://www.milwaukeetesters.com/MW102.html

Adam
 
Also hot tip: Don't buy the stupid sachets of ph calibration fluid-they ALWAYS slowly evaporate; spend a bit more and get a larger quantity in a seal-able bottle or you'll go through fluid constantly and will never have it when you need it.


Adam
 
This is the one I have (and where I got it). Seems accurate enough for my needs, but it IS the only pH meter I've ever owned.

http://www.eseasongear.com/hahipophtehi.html

You will need to buy additional calibration & storage solution.

You made a very wise purchase. Hanna is the big name; they only make quality stuff. 0.02 ph accuracy in a Hanna for $32?!? Unbelievable a few years ago.


Adam
 
Thank you for the tips and input! Only thing is I live in Canada, so shipping is 35$!....

Still looking!

Question though: At ±0.2 ph accuracy, why does everyone hate ph test strips anyway?
 
The big thing (for me) is the hundredth decimal point. You're shooting for 5.4 to 5.6. 5.5 = 5.45 to 5.54 depending on the rounding method they use. I have/had the super cheap Milwaukee. 1) It just died after a few months, but it was $15 so I am not overly concerned. 2) It always drove me nuts to get a 5.4, 5.5, 5.6. Granted, those were acceptable answers. Give me a 5.4 or a 5.6 and I'm all bent of shape. I know I was 5.35 to 5.64, but how close was it. If I came it at 5.5, how close was I to the 5.46 the spreadsheet I use predicted? It drove me crazy. I would also get a meter that has a 2 point calibration minimum. Single point meters calibrate at 7. Dual point will use 4 as the low point, which gives you better accuracy down where you are measuring. Myself I just got a lab grade meter of ebay that is likely overkill, but that is me and there is nothing I can do about it. From my research, however, either go with the above advice of a decent disposable, or at least look for separate temp and ph probes, it reduces the cost of the replacement ph sensor down the road.

And to anser your question, +/- 0.2 isn't so good when you are targeting a 0.2 range.
 
That’s crazy. I suppose it’s a case of marketing run amok. Why would you have a .01 resolution if the basic accuracy is forty times that?

Bear in mind that you will need to spend $30 on buffers and storage solution. I bought the Milwaukee MW101 and it was about a hundred dollars for everything. I like it a lot.

The MW 101 is very similar to the MW102 that biertourist is complaining about. I think he may have unreasonable expectations, all pH meters are slow. It can easily take five minutes for a reading to stabilize.
 
Resolution of 0.01 and accuracy of 0.2? What in heaven's name does this mean? The only thing I can think of is that the meter is very unstable i.e. that put into a buffer the readings will jump around over a set of readings such that their standard deviation is 0.2 pH. This would render such a meter pretty useless in brewing (just as the strips with comparable reading errors are pretty useless).

Response time is a function of the design (read 'cost') and age of an electrode. Manufacturers of 'fancy' electrodes often brag about their offerings response times and usually do so by showing a plot of a series of pH readings over time. It's hard to assign a number which is why the plot is usually offered.

As an electrode ages the response time slows and this is often a sign (reduced slope is another) that it is time to replace the electrode. A new electrode should be within 0.02 pH units of its steady state reading within 30 seconds. This is my personal opinion so don't get the idea that it is IUPAC guidance (if they have any I don't know what it is). It may take as long as 4 or 5 minutes before the last 0.01 of pH change disappears. Beyond that one starts to think about electrode drift as well as response time. A recheck of one or more buffers is a good idea if this is the case.
 
On cheap meters: I bought a Hanna 98107 from Amazon for $40 ~2yrs ago and have brewed 20 batches using it. It reads with .1 accuracy. It needed to have the electrode seasoned in storage solution overnight to calibrate correctly. After that, it has worked flawlessly. It reads pretty close(within .1) of what EZ water predicts with RO and modest CACl2, CaSO4, acid malt, and phosphoric acid additions.

On brewday, it has never read more than .1 off when I'm calibrating it and 97% of the time has not even been off at all. I keep it stored in storage solution and rinse with D/I water in between readings, mix powdered capsule buffer solutions ~ every 3 months or so and it's been a really good cheap meter.

My beer is good, no astringency and I brew mostly light lagers. Recently one scored high 30s with 3 BJCP judges--only dinged for a little acetaldehyde thrown by some cantankerous WY2278 that crapped out at the end of fermentation.

I know my meter could be better(only reads to .1), but it's what I could afford at the time and it works great. Over the last 3 months or so it has taken a little more time to settle on its reading but when it settles, it stays there and doesn't drift. I have no regrets on buying this meter and would recommend it to anyone on a budget.

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That’s crazy. I suppose it’s a case of marketing run amok. Why would you have a .01 resolution if the basic accuracy is forty times that?

Bear in mind that you will need to spend $30 on buffers and storage solution. I bought the Milwaukee MW101 and it was about a hundred dollars for everything. I like it a lot.

The MW 101 is very similar to the MW102 that biertourist is complaining about. I think he may have unreasonable expectations, all pH meters are slow. It can easily take five minutes for a reading to stabilize.


I'm not specifically complaining about the Milwauwkee MW102; just complaining about how long it takes to get a ph reading today in general. (Yes, I do have unrealistic expectations, but wait a couple of years and they'll be faster.) --This was the context in which I made my recommendation of getting the Hanna meter -then in 2 years you get to upgrade to the newer faster technology.

Adam
 
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