Apera Instruments SX620 pH Pen Tester Kit with 0.01 pH Accuracy, 3-Point Auto. Calibration, ATC

Easy to use, appears to be accurate and truly beats the cheap $10-30 meters that are unstable and can take minutes to indicate a fixed reading. This instrument gives a presumably accurate result almost immediately. Supplied calibrating solutions are sparse but can evidently be reused if the probe is carefully cleaned as directed. A single multi-function button that works well replaces the two or three often present on other models. Allegedly waterproof, and the probe is replaceable. Sealing probe cap holds supplied soaking solution to protect and prolong life of electrode. Extra batteries supplied are a plus. Good instructions and warranty. Factory calibrated and even has its own serial number. Not a professional device that can cost hundreds, but certainly worth its price.

At first, I thought this was a good product. It seemed to calibrate easily. It worked for about 2 years and then it didn't . It acted like the batteries were dead, it would turn on and then turn itself off like the batteries were low. I took the batteries out and tested them and they were nearly perfect. I put them back in, same issue. I switched to new batteries same thing. Then it finally started turning on and the ph counter was swinging all around up and down like crazy before maxing out at 15. Turning it on and off many times it did more inconsistent crap. Then I thought it was working again so I tried to calibrate it with ph 4 solution. It registered it as 10 ph and calibrated to that. Tried the 7 ph solution it calibrated to 10 again. I contacted support and they told me I needed a new probe. I check the price on their website $48 plus shipping for a new probe $55 on Amazon. So a new meter is $69 and a replacement probe is $55? Get real and I don't even know if the probe is the problem. I started reading comments on the replacement probe and many were stating they had the same exact weird problem I had. They had bought the probe in hopes of fixing their meter only to find out that it was the electronics, not the probe. Then when they contact support they are told it is their fault, they must have gotten the meter wet. I'm now not sure how accurate this meter is because I have no way to test it anymore and it didn't occur to me in the past it could have been off. But looking back now it did seem to almost always give similar results when testing soil ph. I'll be going back to the cheapo Ph meters until I can get the money to buy a really nice one that is not made in China. I could have bought 7 cheap ph meters for the price of this junk. I thought I would try moving up to a better meter. I should have spent a little more at the time to get something of true quality. The cheap ones work as well as this one, but this had the fancy skinny probe to fit in test tubes so I could use smaller sample sizes. It just sucks this wasn't the quality product I was hoping for. Avoid this Junk meter. If replacing the probe worked I'd try it, but I don't want to spend $55 just to have to turn around and send it back. This thing is acting like it is an electrical issue, not a probe.

The item arrived earlier than expected and comes well packed. I like that it is lab grade with a certificate of quality control and calibration date. The meter itself is very well made and doesn't feel cheap. It has a built in thermometer which is not necessary for my use but very convenient. the calibration and solutions were sealed tight and did not leak. The kit includes 2 extra batteries which is nice. The instructions for calibration are very clear & easy and takes about 2 mins to do. My only complaint is that the protective cap on the ph meter probe was not on tight and the soaking solution that is used for long term storage, leaked out and crystallized. The kit does come with a bottle of soaking solution so i just had to soak and clean the probe before calibration.

I have absolutely no idea how I lived without this pH meter. I had only used older technology, or the cheap yellow meters seen everywhere (which are fine for telling the difference between lemon juice and drain cleaner occasionally). I knew that this one would be better, but I didn't know how much better. Wow. I can actually see the pH change as I add uL of acid or base. I no longer have to put the dumb yellow pen or giant 1980's pH meter in the solution, go drink a cup of coffee, add a reagent, drink another coffee, see if the reading has changed, drink more coffee, read the meter and compensate the value for temperature with a table or calculator... I never trusted digital pH meters too much and used to do a titration or at least double check with litmus paper. This meter is dead on, and I have no idea how I lived without it. Although I've only used the +/-0.01% version, I'd say it's worth the extra $20 if you need precision. This model is small, and may not be as rugged as the larger models, but it does fit in test tubes, and can fit in a buret clamp on a lab stand. Very nice. If I ever need ORP, salinity, or any other meters, I'm definitely going to go with Apera again.

Extremely accurate, well made design and worth the extra money. Carrying case and even neutral solution for storage. Calibration solution was included as well. You get what you pay for.

Seemed like a quality meter, sometimes the reading would creep up or down. Finally it crapped out on me and will not calibrate and the power button stopped working right. When it worked I felt like it was fairly accurate. Not sure if it is worth the $$ given how long it lasted but it doesn't look there is much better out there around this price point.

Update: I contacted Apera directly and they sent me a new unit. The new unit works perfectly. Significant time saved on ph testing (avg. 10 seconds for stable reading) & calibration (avg. 1 second for calibration), compared to the $20 pen testers I've used in the past. I would definitely recommend this product. Original review: I've gone through 6 sets of batteries with this device in the past month. If batteries are left in device, they are spent within 24 hrs. Now the return window is closed, so I'm stuck with a defective device. Unfortunate because it reads very quickly and is extremely simple to calibrate.

Device defective upon arrival. Will read pH of 7.0 no matter what type of solution you place it in. It reads temperatures quite nicely but $60 for an electronic thermometer is a bit much. It's a shame because it seems like a nice unit, if only it worked. Wonder about their quality control.