Recommendations for new pH meter?

[Chuck E]

Hi All,
I crave a Vinmetrica meter, but unfortunately my budget does not permit the splurge. Looking on Amazon, the cheap pH meters seem to get fair to poor ratings.

Can anyone recommend a decent pH meter under $100?

 

[cmason1957]

https://www.amazon.com/dp/B0009YH06Y/?tag=skimlinks_replacement-20

Milwaukee MW101, for just a few dollars more you can get temp also with the MW102.

 

[Rice_Guy]

For $70 I got an Extech. It can take other probes as ORP, the “bulb” is actually flat glass so it can give a pH on 2 drops of liquid, it is break resistant if you put it in a beaker with a magnetic stir bar.
I used pH in the pilot plant testing food coming off the line for 20 years. The cheap ($100) ones work well, I like gel filled so I don’t have to worry about refilling.
I would like a vinmetrica too. SO2 takes a micro amp probe.

 

[Raptor99]

I've been using a $30 pH meter from Amazon, and it sometimes gives wildly inaccurate readings. I re-calibrated it two days ago with fresh buffering solution. Today the 4.0 buffering solution reads 4.15. I no longer trust the readings from this pH meter.

Which Extech model are you using? I found two on Amazon: pH100 for $88.66 and pH110 for $134.46. https://www.amazon.com/Extech-PH100-ExStik-Waterproof-Meter/dp/B00023RYQ8/
I like the idea of the flat electrode, so I can measure pH with a very small sample.

How long have you had it? Does it hold up well? Have you ever had to replace the electrode? I found an electrode for the pH100 on Amazon for $44.99

I welcome any suggestions that others have for a pH meter for under or around $100.

 

[Rembee]

This is the one I have. It is very accurate and I've had no issues with it. It $79.75 on Amazon. It's the Apera Instruments AI311 Premium Series PH60 Waterproof pH Pocket Tester Kit, With a Replaceable Probe.

https://www.amazon.com/gp/aw/d/B01ENFOIQE?psc=1&ref=ppx_pop_mob_b_asin_image

 

[Rice_Guy]

I have had an Extech PH100 for seven years. Since getting it I have added an ORP probe and three years back got another probe when a juice buy had unusual pH readings, ,,, turns out everybody testing their buckets was +/- 0.07 so the probe wasn’t the issue. This spring the probe still matches other folks and the new probe is still in the box.
A dirty probe will stabilize slower and I see it has slowed.
, <= ,YUP ,, small samples
I found it useful to collect a set of tall round bottom glasses to titrate in so that the unit could stand by itself.

The unasked question, , , yes I would buy it again. That said in the pilot plant the $119 meters from Fisher and Cole Palmer also last for years. The round bulb may be more breakable but I haven’t had an issue. again dirty is the issue.

I've been using a $30 pH meter from Amazon, and it sometimes gives wildly inaccurate readings. I re-calibrated it two days ago with fresh buffering solution. Today the 4.0 buffering solution reads 4.15. I no longer trust the readings from this pH meter.

Which Extech model are you using? I found two on Amazon: pH100 for $88.66 and pH110 for $134.46. https://www.amazon.com/Extech-PH100-ExStik-Waterproof-Meter/dp/B00023RYQ8/
I like the idea of the flat electrode, so I can measure pH with a very small sample.

How long have you had it? Does it hold up well? Have you ever had to replace the electrode? I found an electrode for the pH100 on Amazon for $44.99

I welcome any suggestions that others have for a pH meter for under or around $100.

 

[Raptor99]

@Rice_Guy Thanks for your detailed response! I had to look up ORP. It sounds like you can use that probe to measure free SO2. Is that correct? Do you still need to do titration? I'm not sure how that works. I see the ORP probe for the PH100 on Amazon for $60.

 

[Rice_Guy]

NO, , the Vinmetrica probe is measuring micro amps & that was my hope when purchased.

I had to look up ORP. It sounds like you can use that probe to measure free SO2. Is that correct? Do you still need to do titration? I'm not sure how that works.

If you are interested in more info there is a winery grade, instant, single drop, $1K, tool available. Would need to check but think the vendor was Hatch.

 

[pproctorga]

I've been using $13 this one for several years and still spot on for measurements. It lasted longer than my expensive one.

https://www.amazon.com/High-Precisi...ild=1&keywords=ph+meter&qid=1622812223&sr=8-3

 

[BarrelMonkey]

I found it useful to collect a set of tall round bottom glasses to titrate in so that the unit could stand by itself.

It seems like you answered this question already but - can you really do titrations with this sort of instrument? So, for example, TA measurement by titrating in NaOH from a burette into a stirred wine/water solution? I too am in the market for a pH meter some time this year, was leaning towards the Milwaukee model that several here have recommended...

 

[BarrelMonkey]

I've been using $13 this one for several years and still spot on for measurements. It lasted longer than my expensive one.

That's amazing if it's as good as you say... I mean I could just buy a new one every year or two and still come out ahead compared to a cheap probe meter! And I just checked your Amazon link and it's on sale for $10.98. At that price I may get one just to play around with and compare to the one I use at the winery.

 

[Rice_Guy]

you can do TA with any pH meter, the only magic on Vinmetrica is it beeps at pH 8.2.
I rarely (ex sweet potato/ persimmon/ mambey) add distilled water since the probe is flat.
i am old school with two burettes, but swirling a syringe/beaker with hand is faster, you need a burette.
pH technology is old and established, a $10.99 meter should work better than the transistor version from when I was in school.

It seems like you answered this question already but - can you really do titrations with this sort of instrument? So, for example, TA measurement by titrating in NaOH from a burette into a stirred wine/water solution? I too am in the market for a pH meter some time this year, was leaning towards the Milwaukee model that several here have recommended...

 

[BarrelMonkey]

you can do TA with any pH meter, the only magic on Vinmetrica is it beeps at pH 8.2.

I also used pH meters in my previous professional life in a biochemistry/molecular biology lab, but I guess technology has moved on... Thanks for the picture, good to know that that method works!

 

[TurkeyHollow]

I own one of these and am pleased with it: Hanna Inst pH. They have all kinds of winery & brewery test devices but this is a great pH meter (with temp) for around $100.

 

[BarrelMonkey]

I've been using $13 this one for several years and still spot on for measurements. It lasted longer than my expensive one.

So... I bought one of these cheap pH pens just to check it out. I'm not sure if it's the exact model used by pproctorga; there are seemingly a dozen brands on amazon.com that all look alike, I'm sure they all come from the same factory in China. My first day impressions:

- The package came with a pH pen, 3 buffer powders and instruction sheet. There was also an envelope saying 'Please check the warranty card inside'; this had no warranty information but indicated that I could receive a $30 Amazon gift card by contacting them. A little digging around suggests that this is their way of trying to get me to leave a 5-star review on Amazon. Not a great first impression.
- I made up the buffers in 250mL each distilled water as directed. I left the probe in an aliquot of the pH 4.00 buffer for 45 minutes in case the glass bulb needed rehydrating. Nominal pH reading at this stage was ~3.1-3.2, though I wasn't too concerned as I would always calibrate before use in any case.
- I used a wash bottle of distilled water to clean the probe between measurements. The instructions say to wipe the probe clean, though I don't think this is a good idea: you shouldn't touch the glass bulb on a pH probe.
- Calibration involved placing the probe in the standard buffers for a few seconds while stirring gently, then holding the CAL button for 5 seconds. The instrument is supposed to autodetect which buffer you're using. The instructions say that just one buffer (6.86) is sufficient for accuracy of +/- 0.1 pH unit, but to calibrate in all 3 buffers for maximum (+/-0.01) accuracy.
- Calibration in the 6.86 and 4.00 buffers seemed fine, but I could not get it to register the pH 9.18 buffer. Following the 2-point calibration, the value of the third buffer seemed to be around pH 9 - but on pressing the CAL button it would always read 6.86.
- I figured that the 2 lower pH points should be sufficient for testing wine samples, though I don't know how their algorithm works; there are no instructions suggesting that you can use just 2 points. Nevertheless I repeated the calibration with the 6.86 and 4.00 buffers, and tested a sauvignon blanc sample that I had lying around. This measured as 3.60, which seemed reasonable; I knew that this particular wine was on the high pH/low acidity end of the scale.
- Repeat measurements of the buffer solutions gave values of 4.03 and 6.87, which I thought were surprisingly consistent.
- Repeating the wine and 2 buffers again gave values of 3.57, 4.07 and 6.92. Again, not too bad for a $10 instrument but maybe a bit drifty.

I think I've learned enough to conclude that while this isn't a total bust, it's definitely a bit squirrely. I would use this to get quick and dirty pH estimates where I didn't care about the 3rd significant figure, but I will look around for a more robust solution for my winemaking endeavors. All of the other options mentioned in this thread (Milwaukee, Extech, Apera, Hanna) seem like they might fit the bill.

 

[Raptor99]

- Calibration in the 6.86 and 4.00 buffers seemed fine, but I could not get it to register the pH 9.18 buffer. Following the 2-point calibration, the value of the third buffer seemed to be around pH 9 - but on pressing the CAL button it would always read 6.86.

I bought this probe as well, and had the same problem. I ended up trying the one point calibration. Afterward, the 4.0 buffer solution read 4.01. Close enough. I'll see how consistently this works over time. I will check it with a buffer solution once in a while to see if it is still in calibration.

 

[sour_grapes]

- Calibration in the 6.86 and 4.00 buffers seemed fine, but I could not get it to register the pH 9.18 buffer. F

I had a similar problem. IIRC, it "autodetected" my 6.86 as the 4.0 standard. Hence, everything read VERY low pH. I tried many tricks to try to convince it otherwise, and to recalibrate, but I couldn't do so. I basically gave up on it.

 

[Snafflebit]

I am enjoying the Apera AI311. For what it’s worth. Calibrating with two standards will allow the instrument to do a straight line fit of the response curve of the probe and 3 standards allows a parabolic fit which is more accurate. But, since wine is measured around the 4 pH standard, the 9 pH standard will have little effect on calibration.

 

[Rice_Guy]

As @Snafflebit said wine is less than four, why do you care? ,,, unless you are also making nixtamil for corn tortillas, or soap.
The electronics in a meter is remembering the millivolt potential generated with those two buffers and drawing a straight line between them to interpolate all other readings. YES the glass bulb is fragile and should not be touched. YES I kept a distilled water wash bottle on the pilot plant floor for cleaning the probe. and YES a cheap probe with a good glass bulb should last for years.

 

[BarrelMonkey]

As @Snafflebit said wine is less than four, why do you care?

Just reporting my findings in the hope that they may be of use to others. I do agree with you that 2-point calibration is sufficient; previously I've only ever calibrated meters at 4+7 or 7+10 depending on the pH range I wanted to measure. I would even argue that since our focus with wines is pH <4 it may be counterproductive to add a high range point, since any error in this will have a bigger effect on measurements at the low end of the range.