Against my better judgment after reading critical reviews, I pulled the trigger on this product and bought a couple sets. I was happy with the results for my specific use-case. I calibrated the devices using the stock calibration solutions in 250mL of distilled water (tap water will throw off your measurements) and it was mostly fine. The problem was that one of the pH meters wouldn't calibrate at the 9.18 calibration point and only recognized it as 6.86. This was a red flag at first, but it didn't appear to matter as it measured with the same accuracy with a 2-point calibration as the other pH sensor did with a 3-point calibration. Now, since my measurements were all around 6pH (hydroponics), I found that the readings were very accurate when tested against standards withing 5-7pH, with variance of +/- 0.01, and increasing variance outside of that. pH around 9 was +/- 0.15 on one unit and +/- 0.3 on the one that couldn't calibrate at 9.18. Of note: I found about a 5% variance in the measurements taken with each of the units results compared to each other, meaning their pH sensor manufacturing spec likely has a fairly large tolerance. The EC sensors appear to be consistent with each other and I was able to accurately measure my dissolved solids conductivity using us/cm^2. In short, if your working range is 5-7, this set will be great value for your money. If you're working outside of that range, you may have to spend some more money on a different set. One more consideration is that the pH calibration standards included are non-standard. They are 4.0, 6.86, and 9.18, meaning they will be relatively difficult to find for purchase. My recommendation: make the calibration solutions and store them in a sealed glass container for future calibrations. They will need to be replaced eventually, but at least they're usable more than once. Read more

I bought this set mainly to check the conductivity of my LC coolant in my Ioniq 5. The items arrived quickly and safely in a solid box. It came with full instructions and even an extra set of batteries. I checked the TDS meter using tap water and got an expected reading of 56 (pure distilled water would be closer to 0) us/cm. I am very pleased with the performance and the value. Highly recommended! Read more

Crazy, totally confused even after following instructions Read more

الجهاز لايحتوي على محاليل معايره Read more

As with any digital ph devices that claims it can be calibrated have test strips. This is a good device and great value. It has a shorter life span compared to more expensive models but the lifespan is very reasonable when compared to the savings. But all these devices fail. Have test strips and a small test kit. Test your device occasionally. Save the plants! Read more

TDS meter are working fine but for the PH meter I personally don’t arrive to fully calibrate it as all the time I do the PH 7 then PH 4 and when it’s arrive to do PH 9 it’s return to PH 7 so impossible to complete the calibration. Read more

The PH & EC/PPM meters are worth their weight in GOLD. The meters come in a VERY sturdy box plus detailed separate instructions, the PH meter comes with powders for calibration and the EC meter comes calibrated plus spare batteries for both. I would recommend these, and at a very good price too. Read more

Very good quality Read more

This is not Vivo brand it’s very bad brand and it comes without the calibration Read more

Came with no calibration buffers. Read more

Excellent Read more

its as expected Read more