Cheap Ph Meter Vs. $100 Ph Meter Test

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PGEduardo

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Awhile back I snagged this set for $11:

https://www.amazon.com/gp/product/B013QJ1JO2/?tag=skimlinks_replacement-20

After reading about how finicky Ph meters can be in general, I figured I should spring for a "nice" one and bought a Milwaukee MW102:

https://www.homebrewtalk.com/showthread.php?t=585264

Many have reported that the cheap meters gave up the ghost after only a few batches, but mine seemed to be working OK. I just didn't really trust it and wanted a bit more precision.

I've had the cheap meter for exacly one year and used it for at least 8 batches (always chilling the mash sample first).

First head to head results:
NiceMeter.jpg
CheapMeter.jpg

I ordered a water report a few months ago and have been experimenting with Bru'n water spreadsheets. In my experience, my Ph is always a bit higher than predicted by ~0.1. The spreadsheet predicted 5.2 pH for this batch. I'm sure it comes down to my specific malt/seasonal change in water, but close enough for me.

Notes:
With the MW102, I checked the pre-packed buffer solution and it was out of calibration. I ran through the calibration procedure exactly, but after power cycling, the 7.01 solution was reading at 7.03. 4.01 reading was spot on. Meh, close enough for me and within the 0.02 advertised accuracy. I had used this meter about 3 weeks ago, stored with proper solution in the cap.

Surprisingly, the cheap POS meter was right on with it's calibration right out of the box, even though it had sat for at least 2 months. It's advertised accuracy is 0.1pH, so if we assume the MW102 was correct, the true reading was 5.4 rounded, and therefore the 5.5 measurement was correct.

I'll keep repeating this test for every batch and post here, but in my opinion a proper water report and Bru'n water can hold their own against an expensive meter, and when coupled with a cheap meter, you should be in the right ballpark...

But hey, if you can spare the coin, a nice meter is great piece of mind and two measurements are better than one!

:mug:
 
Last edited by a moderator:
Notes:
With the MW102, I checked the pre-packed buffer solution and it was out of calibration. I ran through the calibration procedure exactly, but after power cycling, the 7.01 solution was reading at 7.03. 4.01 reading was spot on. Meh, close enough for me and within the 0.02 advertised accuracy. I had used this meter about 3 weeks ago, stored with proper solution in the cap.

Surprisingly, the cheap POS meter was right on with it's calibration right out of the box, even though it had sat for at least 2 months. It's advertised accuracy is 0.1pH, so if we assume the MW102 was correct, the true reading was 5.4 rounded, and therefore the 5.5 measurement was correct.

The pH of the buffers depends on temperature, more so with 7 buffer than with 4 so assuming that your meter is perfectly stable and you did the calibration perfectly a reading of 7.03 might be spot on. In judging the quality of the calibration you must take buffer temperature into account. Now it is probable that you did the cal with the buffer at room temperature and then checked at room temperature in which case the electrode has drifted or, more likely, you told it to accept the buffer reading too early. If 0.03 or so error is acceptable to you then that's OK but for best results you should keep the electrode in the buffer for a few minutes before accepting the cal reading. For the finest (lab) work I often wait 5 minutes or more.

Assuming that the Milwaukee is right at 5.35 and the cheapie reads 5.4 then the cheapie isn't right. It is in error by 0.05 pH. Given that you know the Milwaukee is reading a bit high the true pH is doubtless less than 5.35 and had you stayed in the buffers longer during cal that's probably what you would have read. If the Milwaukee read 5.34 would you conclude that this rounds to 5.3 and that the cheapie is, therefore, off by 0.1? That would not be the case. It would be off by 0.06. This is, at least in part (the cheapie may be off from other causes as well) 'quantizing noise' caused by the poor precision of the cheapie. Its magnitude depends on the true pH, obviously, so we can only say that its rms (root mean square) value is 0.029 pH. No matter how good the meter is otherwise it will always have this error.

What is important in evaluating either meter is how well it holds calibration once it is accomplished. Do the stability test described in the Sticky at the top of this forum bur remember that because of quantization a meter with resolution 0.1 pH can never be more accurate than 0.03 pH, even if it is rock solid which the cheapies do not tend to be.

I'll keep repeating this test for every batch and post here, but in my opinion a proper water report and Bru'n water can hold their own against an expensive meter, and when coupled with a cheap meter, you should be in the right ballpark...
It is well known that no spreadsheet or calculator is capable of much accuracy (except under special conditions) and that's why we want a pH meter to check up on the calculated pH. Assuming error in the program of ±0.1 pH and error in a cheap meter of ±0.1 pH (quantizing and instability) it is possible at some times that the spreadsheet error and meter error will cancel telling you that you are right on when in fact you may be off by 0.2 pH and in other cases that you are off by 0.2 pH when in fact you are right on. This is a statistical process we are dealing with here. Don't be lulled by thinking that just because you got agreement in a case or two that you will always have it.

But hey, if you can spare the coin, a nice meter is great piece of mind...
Yes, a meter that passes the stability test and has 0.0029 pH quantizing noise (0.01 resolution) does grant peace of mind.


.. and two measurements are better than one!

In this case they aren't. Looking at just the quantizing noise a single measurement from the 0.01 resolution meter has uncertainty of 0.0029 pH and a measurement from the 0.1 meter an uncertainty of 0.029 pH. The uncertainty in an average of the measurements from each is 0.020 pH; better than ta single reading from he cheap meter but a lot worse than just one measurement from the good meter.
 
Further to the last paragraph of #2: only a dummy knowing that one reading is 10 times less accurate than the other would average the two. The smart guy would add 0.1 times the crumby reading to the good reading and divide the sum by 1.1. If he did that the uncertainty would be 0.029/sqrt(1.1) = 0.028 which is slightly better than the uncertainty in the single reading from the good meter (0.029) but not enough so to make it worthwhile to bother with the cheap meter.
 
An interesting test you did there! Thank you for documenting your process and findings and being so brave to report it here!

Chances are the cheapo meter is a lot closer than a thumb, but a good meter will take the crown any day, every day.

Thanks to AJ for giving the results the correct perspective.
 
Good report. I started with the $15 meter, and like you said, it gave up the ghost after a few short uses in less than 45 days. Rather than spend another $15 with this failure in mind, I went ahead and got the Hach Pocket Pro + Ph and have been happy. I had one of my buddies who tests ph levels in soil and water at Clemson University to double check my meter (he took my meter to his office) and he said I was on the money as verified against lab grade equipment.

Your post was informative.
 
Let's suppose you have a kitchen scale that can be calibrated and that you calibrate it with a NIST traceable 50 gram mass. Sometime later you come back and turn it on and it reads 50.000 grams. You then send it off to NIST and they put a mass on it that weighs 50.00 grams and then put that mass on their latest and greatest watt balance which also reads 50.00 grams. You can then say your inexpensive kitchen scale has been verified against the most accurate scale in the world but you already knew that when the NIST traceable weight read 50.00 grams in your kitchen.

It is the same with the pH meter. When a NIST traceable buffer reads 7.01 in your kitchen you have verified it against lab grade equipment. The tie in to this lab grade equipment is through the buffer. As a pH meter is calibrated against a NIST traceable standard it is as accurate as the equipment used in the preparation/formulation of that standard and it is not necessary to check it against that equipment. The question with pH electrodes is as to whether they will hold their calibration with respect to the NIST standard and the difference between good ones and not so good ones is determined by how long they hold the cal (how stable they are) and that you can easily verify yourself.

The reason for bringing this up here is to assure readers that it is not necessary to trouble your friends with access to expensive equipment to attain confidence in your relatively inexpensive meter. If it passes the stability test to your satisfaction it is verified against lab grade equipment (through the standards, that is, the buffers) and you can be confident in it.

The bad news with pH measurement is that the best electrodes require frequent calibration but the good news is that adequate standards are readily available. Compare to a voltmeter or clock (oscillator) which, once calibrated, are stable for a year or so but require a trip to a metrology lab to calibrate.
 
Let's suppose you have a kitchen scale that can be calibrated and that you calibrate it with a NIST traceable 50 gram mass. Sometime later you come back and turn it on and it reads 50.000 grams. You then send it off to NIST and they put a mass on it that weighs 50.00 grams and then put that mass on their latest and greatest watt balance which also reads 50.00 grams. You can then say your inexpensive kitchen scale has been verified against the most accurate scale in the world but you already knew that when the NIST traceable weight read 50.00 grams in your kitchen.

It is the same with the pH meter. When a NIST traceable buffer reads 7.01 in your kitchen you have verified it against lab grade equipment. The tie in to this lab grade equipment is through the buffer. As a pH meter is calibrated against a NIST traceable standard it is as accurate as the equipment used in the preparation/formulation of that standard and it is not necessary to check it against that equipment. The question with pH electrodes is as to whether they will hold their calibration with respect to the NIST standard and the difference between good ones and not so good ones is determined by how long they hold the cal (how stable they are) and that you can easily verify yourself.

The reason for bringing this up here is to assure readers that it is not necessary to trouble your friends with access to expensive equipment to attain confidence in your relatively inexpensive meter. If it passes the stability test to your satisfaction it is verified against lab grade equipment (through the standards, that is, the buffers) and you can be confident in it.

The bad news with pH measurement is that the best electrodes require frequent calibration but the good news is that adequate standards are readily available. Compare to a voltmeter or clock (oscillator) which, once calibrated, are stable for a year or so but require a trip to a metrology lab to calibrate.

This may be a dumb question but if a pH meter is calibrated using the correct buffers at the correct temperatures, can we assume the pH meter is then good to use for mash readings or are there other variables that would make it look like the pH meter has been calibrated but it still reads the mash pH incorrectly? Another way to phrase that question is, could the pH meter show 4 and 7 when being calibrated but not actually be correct?

Where I am going with that question is, my pH meter is a few years old. I stored it per Hanna's instructions but the storage solution dried up and it was like that for 6 months or even longer. I started using it again the last few batches. I calibrated it before each batch. After calibrating it, I used it about 20 minutes later. Is there anything that can happen to a pH meter that would give out a wrong mash reading even after calibrating it?
 
This may be a dumb question but if a pH meter is calibrated using the correct buffers at the correct temperatures, can we assume the pH meter is then good to use for mash readings or are there other variables that would make it look like the pH meter has been calibrated but it still reads the mash pH incorrectly? Another way to phrase that question is, could the pH meter show 4 and 7 when being calibrated but not actually be correct?

Where I am going with that question is, my pH meter is a few years old. I stored it per Hanna's instructions but the storage solution dried up and it was like that for 6 months or even longer. I started using it again the last few batches. I calibrated it before each batch. After calibrating it, I used it about 20 minutes later. Is there anything that can happen to a pH meter that would give out a wrong mash reading even after calibrating it?

my understanding is that when it's starts drifting and takes forever (longer > 1minute) to settle on a correct measurements - it's time to replace it. But if it doesn't drift and you can calibrate it, I don't see why you shouldn't trust the measurement. Perhaps its not a bad idea to calibrate at say 7.0 and then go measure your favorite commercial beer that you know is, say, 4.3 and see if it is the same. In other words, calibrate more than a single point (most kits come with 2-3 different points for calibration).
 
There are, of course, things that can screw up a pH reading after the meter is calibrated such as a cold solder joint in the electronics, a loose wire in the electronics, electrode or connector, striking the bulb hard enough to break/crack it or a piece of husk material moving over and clogging the junction but once we have a verified cal we assume that one of these things will not happen and trust the readings. With experience you should be able to tell when a pH reading doesn't look right at each step in the brewing process. When a reading doesn't look right the first thing to do is check against the 4 buffer. If it reads 3.5 or 4.5 you know something is wrong. Note that I put "verified" in italics above. The way I handle that is to always start calibration with the 7 buffer and finish with the 4. After the cal, I leave the electrode in 4 buffer and read it several times. Obviously it should read 4. If it doesn't, there is a problem. Obviously this is a mini stability test and we accept that the meter is ready to go if it is stable for a couple of minutes based on the confidence gained from a longer duration stability test that we have run earlier.

If a meter has been improperly stored for some period of time it is proper to question its stability. In such a case you should calibrate and do a long term stability test in order to regain confidence in its ability to take valid measurements during an actual brewing session.

Slow response, reduced slope and increased offset are all indications that the electrode is nearing the end of its service life. But if you are patient (both during calibration and use) you can continue to use such an electrode. Some meters will not allow calibration if the slope drops below 95%. I've always been suspicious that this is to help the manufacturer sell more electrodes but I'm basically a pretty cynical guy.

Two point calibration is essential in brewing as noted in a couple of earlier posts because brewing pH is mid way between 4 and 7.
 
Great info. I'm brewing tomorrow. I'll do a long calibration to see how it does. I do know it took a few minutes for it to reach the right ph so I assume the electrode is at the end of its life but it did reach the two desired readings last time i used it and was only off by .1 for the 7 buffer the time before that (though this is only accurate to .1 so it could be off by .19 but only show that it is off by .1).
 
My concern about pH meters is cost. It seems these things are fragile, kind of expensive and need to be replaced somewhat often.

It just does not seem like a good thing to chase at the homebrew level.

Is there a type of pH meter that is more durable etc... that would require less attention? I can't justify spending $200 and needing to replace a probe every year along with the risk of ruining the probe if the soak water dries up.
 
My concern about pH meters is cost. It seems these things are fragile, kind of expensive and need to be replaced somewhat often.

It just does not seem like a good thing to chase at the homebrew level.

Is there a type of pH meter that is more durable etc... that would require less attention? I can't justify spending $200 and needing to replace a probe every year along with the risk of ruining the probe if the soak water dries up.

They do sell cheaper ones under $80. Mash pH is definitely a concern for home brewers. High mash pH will cause bad efficiency and tannin extract.
 
My concern about pH meters is cost. It seems these things are fragile, kind of expensive and need to be replaced somewhat often.

It just does not seem like a good thing to chase at the homebrew level.
There was a time in my life, and doubtless most people's, when $125 was a big deal and a decisions as to whether to pay the electric bill on time or the phone bill on time had to be made. Fortunately most of us move up over time, despite what the politicians say, and I hope this will be the case for you but if you can't afford one now, defer it.


Is there a type of pH meter that is more durable etc... that would require less attention?

Yes, ISFET. These are basically H+ ion sensitive field effect transistors. They can be stored dry, cleaned with a toothbrush etc. When they first came out I was sure that we wouldn't be using glass electrodes by now but that hasn't proven to be the case. I've had a couple and they eventually fail too and pretty quickly in my experience. I'm sticking with glass for now.


I can't justify spending $200 ...

As pH control is easily as important to good beer as temperature control I often suggest brewing an extra 2.5 gal of beer and drinking that instead of 20 pints of $6 beer at the pub and using the $120 to buy a decent meter.


...and needing to replace a probe every year...

You won't need to replace the electrode every year. Every 3 years now seems to be more common (and I have electrodes that are still in service that are over 6 years old).


... along with the risk of ruining the probe if the soak water dries up.
WIth the Hach pH Pro+ (one of the three meters that has the HBT seal of approval attached to it) you can store the probe dry if you want though most of us put a couple of drops of water in the cap.
 
Thanks for your replies. I just don't want to wander into an area where I invest in a meter only to find I did not treat it properly because I am busy running my businesses. If it is truly use and forget I am on board but if you have to monkey with the thing before and after every brew day and in between then it poses too much of a time cost to me. I will just rely on the software projections and get "close".

So, what is the real maintenance involved with owning a good pH meter?

Thanks for your help!

BTW, the Hach for $120 does look pretty good!
 
Thanks for the replies. I'll keep updating this thread as I brew, and until the cheapo craps out.

The purpose of this thread is to provide practical results for the 99% of homebrewers who do not have engineering design-level knowledge of the meters. I calibrate and use the meters as directed in their operating instructions.

I design and build radiation detection equipment for a living - at the end of the day the end user wants a solid, stable, consistent piece of equipment that is easy to use. It either meets its specs or it doesn't.

There are a ton of theoretical, first principles limitations on the performance of the detectors, but at the end of the day the user/consumer should be able to purchase based on price/specs and expect that their hardware performs accordingly. My goal here is to determine (if possible) if the cheap meters meet their specs. Right now, it looks like my particular unit might, but probably doesn't as I *think* it reads high.

We'll see...
 
With software that helps guide water treatment decisions, a pH meter is not imperative. However, a meter is a good tool for assessing if that software is guiding you well and to help 'calibrate' your pH results with the beer you create. There are a lot of variables influencing mashing pH and it is easy for any of them to shift without our knowledge (ie: water profile, malt characteristics, etc). A program is only as good as the information fed to it and its easy for a prediction to be off. Using a calibrated pH meter is your insurance for knowing...and it provides guidance in correction and refinement.

But not a requirement!
 
Update with Yooper's Oatmeal Stout. Way undershot pH - I hope it turns out alright :mad:

I haven't brewed a ton lately, but hoping to get back into it with some equipment upgrades. I did a blue moon clone awhile back but didn't post results since I mistakenly ordered the wrong pH buffer solutions (4.00 and 7.00 instead of 4.01 and 7.01).

So far, looks like the cheapo is living up to its specs, 5.4 reading versus 5.30 with the MW102:
OatmealStoutMW.jpg

OatmealStoutCheapo.jpg

:mug:
 
...

I did a blue moon clone awhile back but didn't post results since I mistakenly ordered the wrong pH buffer solutions (4.00 and 7.00 instead of 4.01 and 7.01).

...
I'm not an expert on pH measurements, but why would calibrating at 4.00 and 7.00, instead of at 4.01 and 7.01, have any significant effect on the pH measurement of the wort? The slope and intercept obtained during calibration should be nearly identical with calibration points that close together.

Brew on :mug:
 
I'm not an expert on pH measurements, but why would calibrating at 4.00 and 7.00, instead of at 4.01 and 7.01, have any significant effect on the pH measurement of the wort? The slope and intercept obtained during calibration should be nearly identical with calibration points that close together.

Brew on :mug:

Not likely a huge difference, but my goal with this test to is follow the manufacturer directions to the T and determine just how bad a cheap pH meter really is...
 
Go back and look at the pictures in the OP. Note that there is a table printed on the buffer packets. Those tables give the pH of the buffers at various temperatures. They are not constant. 4 and 7 (or 4.01 and 7.01 if you prefer) are nominal pH values at nominal temperatures. Those tables are in the meters' firmware. In calculating slope and offset from calibration voltage readings the pH's of the buffers at their actual temperatures are calculated from the tables data (a polynomial in T^-1, T^0 and T^1 works well). Slope is directly proportional to temperature and the temperature of the buffers may not be the same so it isn't actually the slope that is calculated but the percentage of theoretical slope. Thus a new electrode will measure very close to 100% slope and an older one perhaps 95%. When a reading is made the pH is calculated from the theoretical slope at the measurement temperature multiplied by the percent factor found in the calibration. The voltage from a perfect electrode is 0 at pH 7 and does not vary from this with temperature. In fact it does with one part being due to 'offset' and the other being that the so-called isoelectric pH (the pH at which voltage is not temperature dependent) is not exactly 7. Thus there are actually three pH parameters: slope percent, offset at isolelectric pH and isoelectric pH. To determine isoelectric pH requires readings at at least two pH's and several temperatures and so is seldom done. Rather the meters assume that the isoelectric pH is 7.00. At least I have never seen one that allows the user to set a different isoelectric pH (which is why I do calibration and process readings in a computer for fine work).
 
Go back and look at the pictures in the OP. Note that there is a table printed on the buffer packets. Those tables give the pH of the buffers at various temperatures. They are not constant. 4 and 7 (or 4.01 and 7.01 if you prefer) are nominal pH values at nominal temperatures. Those tables are in the meters' firmware. In calculating slope and offset from calibration voltage readings the pH's of the buffers at their actual temperatures are calculated from the tables data (a polynomial in T^-1, T^0 and T^1 works well). Slope is directly proportional to temperature and the temperature of the buffers may not be the same so it isn't actually the slope that is calculated but the percentage of theoretical slope. Thus a new electrode will measure very close to 100% slope and an older one perhaps 95%. When a reading is made the pH is calculated from the theoretical slope at the measurement temperature multiplied by the percent factor found in the calibration. The voltage from a perfect electrode is 0 at pH 7 and does not vary from this with temperature. In fact it does with one part being due to 'offset' and the other being that the so-called isoelectric pH (the pH at which voltage is not temperature dependent) is not exactly 7. Thus there are actually three pH parameters: slope percent, offset at isolelectric pH and isoelectric pH. To determine isoelectric pH requires readings at at least two pH's and several temperatures and so is seldom done. Rather the meters assume that the isoelectric pH is 7.00. At least I have never seen one that allows the user to set a different isoelectric pH (which is why I do calibration and process readings in a computer for fine work).
So different buffer compositions, even of almost the same pH, would have different variation with temperature, which wouldn't match what the calibration tables expected, so the calibrations wouldn't be valid?

Brew on :mug:
 
Yes, that's essentially correct. Almost all the meters we see discussed here use the NIST traceable operational buffers and that's what they are programmed for. Some of them will also handle the NIST buffers and I've seen at least one cheapo that is set up for the NIST buffers. These are generally the same composition as the operational buffers but are at slightly different pH's (i.e. not the convenient 4, 7 and 10 values). If you were to make up a 4 buffer with lactic acid and sodium hydroxide, for example, and it would be easy enough to do this, its pH vs temperature behavior would not match the pthallic acid data stored in the meter and the ATC would introduce errors because of this. If, however, you did calibration with that buffer and another buffer and measured your sample all at the same temperature you would not incur any error as long as your lactate buffer had the same pH (±0.02 which is how good the pthalate buffer is) as the pthalate buffer. ATC isn't doing any temperature compensation so the fact that your buffer doesn't match what the meter expects doesn't matter. Doing everything at the same temperature is good practice with the operational buffers too because the isoelectric pH isn't always 7.00 as the meters assume.
 
Yes, that's essentially correct. Almost all the meters we see discussed here use the NIST traceable operational buffers and that's what they are programmed for. Some of them will also handle the NIST buffers and I've seen at least one cheapo that is set up for the NIST buffers. These are generally the same composition as the operational buffers but are at slightly different pH's (i.e. not the convenient 4, 7 and 10 values). If you were to make up a 4 buffer with lactic acid and sodium hydroxide, for example, and it would be easy enough to do this, its pH vs temperature behavior would not match the pthallic acid data stored in the meter and the ATC would introduce errors because of this. If, however, you did calibration with that buffer and another buffer and measured your sample all at the same temperature you would not incur any error as long as your lactate buffer had the same pH (±0.02 which is how good the pthalate buffer is) as the pthalate buffer. ATC isn't doing any temperature compensation so the fact that your buffer doesn't match what the meter expects doesn't matter. Doing everything at the same temperature is good practice with the operational buffers too because the isoelectric pH isn't always 7.00 as the meters assume.
Thanks, I think I got it.

Brew on :mug:
 
I have just received a MW102 pH meter, which uses 4.01 and 7.01 buffer solutions to calibrate. I was looking at the Hach buffer powder pillows, which look like a convenient way to store the buffers. The Hach pillows are rated at pH 4.01 & pH 7.00 (NIST) -- is the 7.00 buffer going to be a mismatch for the MW102?
 
I use 2 cheap meters.. The yellow one pictured in this thread and a higher resolution .0x meter... They both do what they need to and have worked well to check mash ph and such and for what I need to make good beer... if I was using them in a lab I would get something better... A brewing friend brought over his more expensive MW meter and we didnt get any added value in using it... It read almost exactly the same at different points even though he just calibrated it before use and mine hasnt been done in 4 months or so. for some reason he didnt want me to use his solution to calibrate mine again... IDK maybe he wanted to be happier not knowing if the extra money he spent was justified for our use or not.
for me this is a plastic bucket vs stainless bucket argument... sure the stainless bucket is nicer and may last longer but I can buy 200 buckets for the cost of one stainless one and they both work just as well at making good beer.

BTW I have had my yellow meter for about 3 years and the red ones for a year and a half or so... I wonder if people who claim they "just died" might have been doing something wrong or tough on them because they were "cheap"
 
I have just received a MW102 pH meter, which uses 4.01 and 7.01 buffer solutions to calibrate. I was looking at the Hach buffer powder pillows, which look like a convenient way to store the buffers. The Hach pillows are rated at pH 4.01 & pH 7.00 (NIST) -- is the 7.00 buffer going to be a mismatch for the MW102?

See #20.
 
No, it's that you have been lucky. There is a chance that your cheapo will last more than a year. It just isn't that likely.

Well being that I have had 2 of them and both still work fine, one being 3 years old and the other 1.5 years old So that said I dont share your biased assumptions or claimed odds...Maybe you or morrey were unlucky? or did you even have and use one of these yourself or are you going on the one persons experience here because it falls in line with what you want to believe?
In fairness we dont even know if that one guy (Morrey) tried replacing the battery. Regardless you already made it very clear you dislike these meters and that you think the op is a"dummy" since you called him one in your second post..

I would love to see something useful to prove your point like say the MW meter dissected next to one of these generic meters so components can be explained and we can see why that cheapest mw meter costs 10 times as much if it performs the same.... and why the cheaper meter is doomed to fail and hated so much even if it can do exactly what it needs to for 90% of home brewers that use one and most of us here are using them for home brewing.

I understand wanting the extra point in resolution but needing more than x.xx is just not justified in this application. and the newer generic meters now have the extra point of resolution over the older model yellow one in the first post of this thread.
 
Sorry, I should have directed you to #22. The NIST 4 buffer is made by adding potassium hydroxide to pthallic acid until pH 4.005 is reached. The NIST 7 buffer is made by adding potassium hydroxide to phosphoric acid until pH 6.865 is reached (at 25 °C). We do not use the NIST buffers because those pH's are inconvenient (or at least 6.865 was in the days of analogue instrument with D'Arsenvol meters as the displays). The buffers we use have pH's of 4.01 and 7.00 and can be thought of as being made from the NIST buffers by adding a little bit more KOH to the two acids than would be done with the NIST buffers. Note that the pH's of our buffers are measured by comparing to a NIST buffer and that what is meant by 'NIST Traceable'.

It doesn't matter whenter Hach adds the acid to the pthallic and phosphoric acids or if Hanna does it, or Omega or Orion or any other manufacturer. What controls the temperature dependence of pH is the temperature dependence of the pK's of pthallic and phosphoric acids and that's the same. It also doesn't matter whether the manufacturer labels the buffers 4.01 and 7.00 (values at 25 °C) 4.00 and 7.02 (values at 20 °). It's still the same stuff. Note also that most buffers are labeled ±0.02 pH as that is how tightly their pH's are controlled at manufacture. One can also buy ±0.01 pH buffers but those are clearly more expensive and equally clearly not worth it especially for those using meters with a precision of 0.1.
 
Well being that I have had 2 of them and both still work fine, one being 3 years old and the other 1.5 years old So that said I dont share your biased assumptions or claimed odds...
You can do a simple experiment to see who has the biased opinion here. Find a mirror or any reflective object and look into it. You will see a fine example of confirmation bias. On a more scientific basis you are trying to draw a conclusion about the universe of cheap meters from a sample size of 2. You cannot do that. If the probability that a cheapie meter will last a year is 32% the chance of having 2 last a year is 10%. That's a small number but if 100 guys bought the same pair of meters you did we would expect that ten of them would still have two working. They are the lucky ones.

Maybe you or morrey were unlucky? or did you even have and use one of these yourself or are you going on the one persons experience here? In fairness we dont even know if that one guy (Morrey) tried replacing the battery.
I neither have one nor am I relying on Morrey's experience. I am relying on common sense and the experience of the dozens of other posts I've seen here and on other sites who have found these meters to be a waste of money. Common sense says that if the minimum price point is about $100 one would have to cut lots of corners to produce something that sells for $10 or $11.


Regardless you already made it very clear you dislike these meters
My goal here is to help people understand brewing science and to guide them in the right direction with respect to the purchase and use of brewing science related equipment. I would be giving them bad advice if I told them to buy $10 pH meters as most of them will be disappointed. Some may get lucky, as you have, but most, judging by what's posted out there, will not be. So no, on behalf of homebrewers everywhere, I do not like cheap meters.

and that you think the op is a"dummy" since you called him one in your second post..
I did not call the OP a dummy and I certainly hope that he did not interpret it that way since that was certainly not intended. I contrasted the way a dummy and a smart guy would average numbers from instruments with known large differences in accuracy. As OP didn't average the readings (he just said two readings are better than one and they are if you average them the way the smart guy does) 'dummy' clearly does not apply to him.

I would love to see something useful to prove your point like say the MW meter dissected next to one of these generic meters so components can be explained and we can see why that cheapest mw meter costs 10 times as much if it performs the same....
The MW101 doesn't perform the same. It delivers 0.01 to 0.02 pH accuracy and the units with 0.1 resolution cannot possibly deliver better than 0.029 if they are as stable as the MW101 and I haven't seen any stability data on them[/QUOTE]


and why the cheaper meter is doomed to fail and hated so much even if it can do exactly what it needs to for 90% of home brewers that use one and most of us here are using them for home brewing.
If it is delivered to Amazon for $8 (Amazon has to make a profit) and it has to be shipped here from China then it's value at the factory loading dock can only be $6 or $7. Thus means that the cheapest possible electronics and electrodes are used. While it is remarkable how low in cost and high in functionality electronics have become it is still true that the more corners you cut, the less the MTBF on a product. So, as I said above, common sense and the experience of the world at large (look at the Amazon reviews for these things) and brewers who have bought them are the place to look. Obviously I am not going to buy 1000 of them and subject them to stability and longevity tests so other peoples experience is the best we can do.

It's probably worth noting here that one of the good meters for about $130 is the relatively new Hach and that while the meter performs well on a stability test there were infant mortality problems with the electrode when it first came out. The company's support was outstanding until the manufacturing (or whatever they were) problems were resolved. You will not get that kind of support on a $12 pH meter.

I understand wanting the extra point in resolution but needing more than x.xx is just not justified in this application.
You aren't going to get better than possible ± 0.018 pH accuracy with ± 0.02 buffers with even the best meters an so a third decimal place is empty precision. But the second decimal place is useful to many brewers. If, for example, you are trying to tweak an acid addition you want to be able to detect changes of less than 0.1 pH. You can, of course, argue that you don't ever do that sort of thing and don't really care of your mash pH is 5.4 or 5.6, just that it is in there somewhere and if that's the case then a cheapie would be fine for you and hey, if it breaks after 3 months it's only $10. This is the 'better is the enemy of good enough' school which school I spent a career fighting so there is my bias.


...and the newer generic meters now have the extra point of resolution over the older model yellow one in the first post of this thread.
If the higher resolution ones last a year and can pass the stability test I'll change my song. Time was, not that long ago, when you couldn't buy a suitable pH meter for brewing for less than about $250. That has come down to about half that and will probably drop again.
 
You can do a simple experiment to see who has the biased opinion here. Find a mirror or any reflective object and look into it. You will see a fine example of confirmation bias. On a more scientific basis you are trying to draw a conclusion about the universe of cheap meters from a sample size of 2. You cannot do that. If the probability that a cheapie meter will last a year is 32% the chance of having 2 last a year is 10%. That's a small number but if 100 guys bought the same pair of meters you did we would expect that ten of them would still have two working. They are the lucky ones.

I neither have one nor am I relying on Morrey's experience. I am relying on common sense and the experience of the dozens of other posts I've seen here and on other sites who have found these meters to be a waste of money. Common sense says that if the minimum price point is about $100 one would have to cut lots of corners to produce something that sells for $10 or $11.


My goal here is to help people understand brewing science and to guide them in the right direction with respect to the purchase and use of brewing science related equipment. I would be giving them bad advice if I told them to buy $10 pH meters as most of them will be disappointed. Some may get lucky, as you have, but most, judging by what's posted out there, will not be. So no, on behalf of homebrewers everywhere, I do not like cheap meters.

I did not call the OP a dummy and I certainly hope that he did not interpret it that way since that was certainly not intended. I contrasted the way a dummy and a smart guy would average numbers from instruments with known large differences in accuracy. As OP didn't average the readings (he just said two readings are better than one and they are if you average them the way the smart guy does) 'dummy' clearly does not apply to him.
The op stated he did something and you replied that only a dummy would do that... I dont know were your from but in my experience most would take that as an insult.. ( understand that you were trying to prove a valid point that his thinking was wrong here but...)

As far as the meter having such a high failure rate I would love to see where your getting this because I read a LOT of ph meter threads here and very rarely does anyone actually post that they use these because they are immediately attacked for doing so.. This is the first thread Ive read where someone claimed it just "gave up the ghost" most of the time its just assumed they would fail by people as they repeat the usual self assurances that you get what you pay for and then the thread goes int why Lab quality resolution of .0000 yad yada yada is better and how thats supposed really have some real reflection on the beer being made..

and your assumptions that corners had to be cut to sell something for 10-15 dollars if others are selling something that does the same thing for $100 is noble thinking but wrong... Its about supply and demand and marketing actual manufacturing costs and quality have little to do with product costs in MANY cases the less common the product the more likely the case... The same reason kids will pay $140 for a pair of nike sneakers that were made for $5 with child labor in china.. or pay almost 1/3rd more for a korean made deawoo because its rebranded as a chevy spark or aveo..
Thats why I stated lets see some real side by side prove instead of assumptions.

The reality of it is the company in china that was likely contracted to build the meters for MW likely designed their own and started selling them as generics or reverse engineered them who knows but I but you wont find anywhere near $90 more in component costs in the MW meter...I bet they are made for $5-10 each.
 
The op stated he did something and you replied that only a dummy would do that... I dont know were your from but in my experience most would take that as an insult.. ( understand that you were trying to prove a valid point that his thinking was wrong here but...)

I'll ask that you go back and reread my last post both because I edited it substantially clearly while you were typing and because you missed the part where I pointed out that the OP did not state that he averaged the two readings - only that two readings are better than one.

As far as the meter having such a high failure rate I would love to see where your getting this because I read a LOT of ph meter threads here and very rarely does anyone actually post that they use these because they are immediately attacked for doing so.. This is the first thread Ive read where someone claimed it just "gave up the ghost"
Really? I've seen dozens. Many in this forum, many in others, many in the Amazon reviews. Go check there.

most of the time its just assumed they would fail by people as they repeat the usual self assurances that you get what you pay for and then the thread goes int why Lab quality resolution of .0000 yad yada yada is better and how thats supposed really have some real reflection on the beer being made..
So you are assuming that there are thousands of satisfied customers out there who are afraid to speak up? The silent Trump voters of the pH meter world! Again, I appeal to your common sense.

and your assumptions that corners had to be cut to sell something for 10-15 dollars if others are selling something that does the same thing for $100 is noble thinking but wrong...
It certainly isn't. I've been in engineering long enough to be able to tell the difference between a well made product and a shoddily made one.


Its about supply and demand and marketing actual manufacturing costs and quality have little to do with product costs in MANY cases the less common the product the more likely the case...
Just curious, do you have any experience in industry?



The same reason kids will pay $140 for a pair of nike sneakers that were made for $5 with child labor in china.. or pay almost 1/3rd more for a korean made deawoo because its rebranded as a chevy spark or aveo..
The object in operating a business is to turn a profit. If you can do that by producing a high quality product priced at a point where the purchase of it makes sense to a business then it will sell. If it doesn't perform, you don't. A meter like the Hach Pro+ is intended to be used commercially and thus, if they hadn't fixed the electrode problem, would have failed. The $12 pH meters are really toys. Look at the Amazon reviews and you will quickly come to appreciate the sophistication of the "Works great - only problem is that you have to calibrate it" reviewer. You will also find that 30% of the reviews say "Didn't work", "Don't waste your money", "Only lasted 3 months" etc.




Thats why I stated lets see some real side by side prove instead of assumptions.
That would require a Consumer Reports activity of some sort. I've said that I'm not going to do it so I guess you will have to.

The reality of it is the company in china that was likely contracted to build the meters for MW likely designed their own and started selling them as generics or reverse engineered them who knows but I but you wont find anywhere near $90 more in component costs in the MW meter...I bet they are made for $5-10 each.

Again I have to ask if you have any experience in manufacturing or marketing of technical equipment.

I think Milwaukee's stuff was at first made in Romania but is now done in Italy. Or is that Hanna?

First off, I don't think Milwaukee makes a pen style but I don't really know about that and in any case we are comparing the ~$100 MW101 to the generic $11 Chinese pen. I have no idea what the markup may be on the MW101 but assuming that it is about at the same rate as the Chinese offering then you have x10 the materials cost assuming that Romanian labour is about the same as Chinese which it may not be. In any case, you have a unit which is much more reliable and appreciably more accurate.

"The bitterness of poor quality remains long after the sweetness of low price is forgotten".
 
Really? I've seen dozens. Many in this forum, many in others, many in the Amazon reviews. Go check there.

Indeed, not only forums and reviews are populated with so many failure stories, I own two of the cheap-o pH meters I got for maybe $12 and $20 on amazon before I knew any better.

Both were unreliable and basically stopped functioning properly within a month or two.

I got Miolwaukee pH58, and perhaps I should have invested in pH102, and that pH reader works like a charm for ~ 1.5 years now.

Anecdotal evidence, sure, but if you look around the interwebs, its mirrored by numerous experiences from many users.
 
The Hanna HI 98121 that I bought 3 years ago is accurate enough for my homebrewing needs and continues to work reliably today. I replaced the original ph electrode that came with the meter after experiencing some calibration issues. It pays to buy the pH electrode cleaner and storage solution recommended by Hanna, once I did, the electrode that I had replaced worked again and I now use it as a spare.

I understand that it is what you like and what can afford in life that drives most of our buying habits, but experience has taught me that you get what you pay for. Higher priced meters provide greater accuracy, automated calibration, replaceable electrodes and superior customer support to name just a few of their benefits.

Never being one who deliberately engages in contentious dialog, my suggestion to anyone who is happy with their meter should consider themselves to be very fortunate. Although the idea of comparing the performance of a $10 instrument to that of one costing 20 times that price, is in itself a position that is not easy to defend.
 
I'll ask that you go back and reread my last post both because I edited it substantially clearly while you were typing and because you missed the part where I pointed out that the OP did not state that he averaged the two readings - only that two readings are better than one.

Really? I've seen dozens. Many in this forum, many in others, many in the Amazon reviews. Go check there.

So you are assuming that there are thousands of satisfied customers out there who are afraid to speak up? The silent Trump voters of the pH meter world! Again, I appeal to your common sense.

It certainly isn't. I've been in engineering long enough to be able to tell the difference between a well made product and a shoddily made one.


Just curious, do you have any experience in industry?



The object in operating a business is to turn a profit. If you can do that by producing a high quality product priced at a point where the purchase of it makes sense to a business then it will sell. If it doesn't perform, you don't. A meter like the Hach Pro+ is intended to be used commercially and thus, if they hadn't fixed the electrode problem, would have failed. The $12 pH meters are really toys. Look at the Amazon reviews and you will quickly come to appreciate the sophistication of the "Works great - only problem is that you have to calibrate it" reviewer. You will also find that 30% of the reviews say "Didn't work", "Don't waste your money", "Only lasted 3 months" etc.




That would require a Consumer Reports activity of some sort. I've said that I'm not going to do it so I guess you will have to.



Again I have to ask if you have any experience in manufacturing or marketing of technical equipment.

I think Milwaukee's stuff was at first made in Romania but is now done in Italy. Or is that Hanna?

First off, I don't think Milwaukee makes a pen style but I don't really know about that and in any case we are comparing the ~$100 MW101 to the generic $11 Chinese pen. I have no idea what the markup may be on the MW101 but assuming that it is about at the same rate as the Chinese offering then you have x10 the materials cost assuming that Romanian labour is about the same as Chinese which it may not be. In any case, you have a unit which is much more reliable and appreciably more accurate.

"The bitterness of poor quality remains long after the sweetness of low price is forgotten".
Well its been three years and so far I guess still only feeling the "sweetness" of the money I saved in not buying over the over the top equipment I would never enjoy or utilize to its potential for brewing beer. Unlike you I am speaking from my own experience using these meters and I would know if they are working correctly for me.. The only reason I had bought 2 at all was because after reading threads like this here I was wondering how accurate and how long these would stay calibrated so I use them both periodically to check them against each other and when they are out of sinc I recalibrate. them.

I dont know what amazon reviews your refering to because I just looked and these almost all have 3.5 stars or more which is actually very high for something so low cost and entry level... as a matter of fact being that these are so cheap it wouldnt be surprising if they got a lot of bum reviews both good and bad from people new to having a ph meter and their limitations... I bet if you were to offer a similar higher priced meter with the built in probe for the same price you would see similar complaints from these same people due to their inability to read directions or understand how to use them.

When people drop more coin on something they are more likely to do a little research or at least read the directions beforehand and these is apparent by some of the reviews you read form places like you tube and amazon... There are some that just complain regardless to see what they can get from the seller out of it.

:off: But since you asked more than once were im coming from and my experience Ill get on my soapbox once again. I work in the commercial printing field now and actually spend time in one of our manufacturing plants up in canada last week for the company I work for now..
I worked in a field where Ive dealt mainly with engineering and design departments of all types for the last 20 years... Since nafta many have begun singing a common tune as their factories close up and they outsource most of their products to manufacturing and even engineering overseas... Since the engineers are usually the last ones to go before the management to line the stockholders pockets they are usually pretty open to discussion and complaining while im there putting say a $14 part they are paying 4 or $500 for because thats what it costs after going through multiple markups from the equipment manufactuers and resellers that may rebrand it and of course my employer... and lets not forget depending on which company that customer may have called to place the service call they were being charged anywhere from 150 to $285 an hour for me to be there since we were "VIP" dealers for a large printer company and sometimes we were obligated to be contracted out do do the servicecalls for the customers who believed they were dealing directly with the manufactuer (wrong since the equipment was rebranded) for service (Wrong again ) of course we couldnt tell them that we were really a dealer and they could call our own service number and have been charged half the rate...

Anyway I would hear quite often in conversation while repairing equipment about how a company has started outsourcing some of thier product line to take advantage of a well known name by modifying a generic pump or or just repackaging and selling generic chinese designed stuff since the profits were much better and they didnt have to deal with manufacturing costs some even closed up local manufacturing completely or were bought by a larger competitor who did so and they (the engineers) are kept around for quality control, occational design changes and such... after a while you see the common trends. Like 5 out of say 7 of the local steel companies I deal with all buy and resell the same chinese steel often because their margins are higher. (I may be exaggerating a bit to make my point because I only asked a few where they get it.)

I also repair electronics like flat screen tvs as a hobby and for extra money... I know how in this industry they will often sell the same tv from one of the 4 or 5 manufacturers that make components, repackaged and sold at all different pricepoints to unsuspecting victims that believe you always get what you pay for and shop by brand names they remember as being popular regardless of whether those brands even exist anymore besides on paper only to be leased by whomever want to use them to peddle a cheap chinese tv... heres an ironic thing... if you look inside most vizio tvs your see they are made of LG components and are the same as the cheaper model LG counterparts but if you open a higher end LG set youll find mostly samsung conponents) Ive made some Frankenstein tvs by swapping motherboardboards from one set to another since this or even just the firmware along with the case and remote is often the difference between a $300 tv and a $600 tv especially now in the throw away led garbage tv environment we are in now. I used to be a tech instructor for a printer company that would sell the same printers sold as 4 different brand names with different prices and dealer support, Ive worked on hp printers that were made by epson xeroxs made by fuji or kip, kodaks made by hp or screen and seen when companies like hp and xerox decided the money they put into marketing is more important than having anything to do with actually designing or making the products they are selling...

The reason for my rant was to point out that Based upon my experiences, It just as often all about perception these days. Things like marketing tactics, secretly owning multiple competing brand names and price setting has become more important to quality and you have different generations of thinking some now outdated... and a whole market segment designed to take advantage of those peoples outdated perceptions that you get what you pay for and it its got a certain brand name on the box its better than another product based on that and the higher price. Even when that just as often completely untrue.... It would be more true to say you dont always get what you pay for but you never get what you dont... and the catch to that is you have to know what your buying really costs to manufacture..

Want an example? anybody want to buy an edenpure heater? its $400-600 compared to all those cheaper knockoffs for $120 at the bargain store and ive seen all those commercials bragging about them so it must be better right?... Nope. your just paying for the commercials to help hype them up..

In this case I bought a couple $12 ph meters that I really believe work just as well for my needs as any other comparable cheaper meter like the hanna meters and such that sell for 6-10times as much for the same tech.. Even if the hanna is made to hold up better and it might be, Ive seen many people complain of issues and frustrations with the probes and eventually ditch them for something else. So if Im having perfectly good performance out of my $12 meters why would I change them? I dont need higher resolution and no one has shown any proof whatsover that a person could detect any difference in a beer with a mash ph of 5.4 vs 5.35. again its all been speculation and assumptions until someone proves it.
And am I really only that lucky twice over? Sorry but I believe there is some heavy bias in this thread and ill admit I responded with the same only based upon MY ACTUAL experience with the meters in question. Not an amazon review.
 
In this case I bought a couple $12 ph meters that I really believe work just as well for my needs as any other comparable cheaper meter like the hanna meters and such that sell for 6-10times as much
If you really believe it then it is true - for you. My job here is to present information which will allow others to make an informed decision. This means I have to put your belief into perspective considering the information available to me which is based on years as a practicing engineer many of which were spent in acquiring and integrating test equipment of various kinds into systems that required high reliability. If something failed I had to put a guy on a plane to the Middle East (or go myself). This did definitely bias me away from poorly made gear and while a high price tag didn't always guarantee better performance or reliability, a price tag out of line with industry standards always guaranteed the converse. I have also experimented with very good and very bad pH meters. People bring their cheapies to me and ask me to check them out and I have bought a couple. I also know how pH is used in brewing (0.1 pH isn't really adequate resolution - but if you feel it is that's fine for you), and have an in depth knowledge of the art of pH measurement. Most valuable is the reported experiences of others, especially brewers i.e. people that are using the products in the application under discussion. The negative Amazon reviews are useful as it doesn't matter what the application is if the thing died a month after the guy got it or was dead out of the box then it is dead whatever his application. The positive reviews need to be taken with a grain of salt because people who buy $12 pH meters by and large don't know much if anything about pH an the art of its measurement. "Works great" is not terribly informative but Helmut Galster (author of a book on pH measurment) could post such a review. "Would have given it 5 stars except to have to calibrate it every few month" is more telling.

Finally, people should use their common sense (which, apparently, most do).

...for the same tech.
You seem to be under the impression that a $12 pH meter and a $100 pH meter is the same with the extra $88 going for marketing and relabeling. Holding a high quality meter in ones hand and a cheapie in the other it is clear that this is not the case. The differences in 'build quality' are obvious. Yes, both devices will use an instrumentation amplifier, an A/D converter, a microprocessor, a display and an op amp (for the RTD) and some of those components may even be the same but the heart of a pH meter is the electrode. While it is true that a better design may contain buffer recognition features and have amps and A/Ds with finer resolution, less offset and better noise figure the real difference between a $12 meter and a $120 meter is the difference between a $6 electrode and a $60 electrode. Electrode manufacture is an art.

I often suspect that these real cheapo makers are buying electrodes intended for better meters that failed to meet specs. If you have made 1000 electrodes that you intend to sell for $50 and half of them are not sufficiently stable (it's all about stability - any electrode that can produce 57 mV/pH is perfectly accurate at the time of calibration) for a 0.01 resolution instrument you can throw them away or you can sell them for $2 and recoup $1000. The manufacturer can then get $2 electrodes which work well enough to justify 0.1 resolution. This is all speculation on my part but I'll note that this was exactly this mechanism whereby Radio Shack got the electronics parts it sold in its stores (and probably put into its products as well).

I any case, I admit my bias towards well made, reliable, accurate products and, as $12 pH meters are none of the above continue to advise against them. OTOH, if you get a bad one then its only $12 - unless it dies in the middle of a batch and sets you chasing bad pH. Ideally always do a 2 point calibration before each brew or at least a pH check in both buffers.

And am I really [the] only [one] that lucky twice over?

I tried to explain in an earlier post that you aren't. Think of each meter as a coin and toss a pair of them. Tails represents a meter failure before the end of a year. Heads means it lasts longer. You have made a single toss. The probability of two heads is 25%. If you do 1000 tosses you will get something close to 250 double head events. So if the probability of failure in the first year is 50% there is still a pretty good chance you could not have a failure in either. If the probability of failure in the first year is 90%, OTHOH, the probability that you would have two working units at the end of the year would be 1%. Then we would have to call you unusually lucky but in a group of 1000 buyers of the same units you would still have 9 buddies.
 
Brewing up a simple NE style IPA tonight. I picked up a new cheapo $11 meter from Amazon just for $hits and giggles. Using the MW solutions to calibrate (4.01 and 7.01), all meters still appear to be meeting their specs.

:mug:

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WIth the Hach pH Pro+ (one of the three meters that has the HBT seal of approval attached to it) you can store the probe dry if you want though most of us put a couple of drops of water in the cap.

I am in the market for a meter.
What three meters have this "seal of approval"?

Thank you.
 
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