Review on HM Digital Waterproof pH and Temperature Meter, 3.3 x 8.5 x 2 inches, White by Paul Romero

One of the things I was looking for in a pH knob was a relatively quick reading, maybe around 15-30 seconds. This meter will slow down significantly after 30 seconds and then drift toward its final reading for perhaps 15 minutes or more, to a drift of 0.5 or more. It's frustrating to make an addition and then have to wait long enough to get reasonably accurate readings before trying to adjust again. Yesterday it took me over two hours to test and optimize 4 solutions (each with several adjustments). It was disappointment that made me take the time to write this review. I used to assume it was exactly 30 seconds or so, but I've encountered some pretty serious issues with the solutions I've used. I didn't assume it was the pH because this meter indicated I was within the specified range. The results indicated pH quite strongly though, so I calibrated the pen as usual (it almost didn't turn off) and then retested all the solutions, but this time I gave them quite a while for the meter to settle . I was shocked at how inaccurate the initial readings were and how far they kept drifting before finally settling on a reading. These were solutions with a temperature of 68 degrees and a pH of 5.5 to 7.5, so nothing extreme. I have had the device for about 16 months now and am very careful with the storage solution after each use etc. I calibrate it regularly and take very good care of it. I do a lot of research before I buy anything and I'm usually very happy with what I choose. Needless to say I am disappointed this time. If you are looking for a fast and accurate measuring device, you can look elsewhere.