Afkka PH Meter, 0.01-14.00 pH High Accuracy pH Tester, 2% Reading Accuracy PH pen, ph Probe pH Tester for Water TDS Meter Digital Water Quality Tester 0-9990 PPM TDS & EC LCD Water Purity Aquarium

This can be a useful option for anyone looking for something portable with value for money. Comparable in quality to more expensive options

I didn't know you could get electronic pH testers, but having recently started a low-acid diet to try and help my reflux, I was keen to give this a try.I wasn't actually convinced this would work, but it does. I'm not completely sure how accurate it is, as I have nothing to compare it with, but when I add stuff I know to be acidic, such as vinegar, to a glass of water, the pH drops significantly, so it's clearly detecting the acidity.The issue is, the calibration doesn't seem to be working for me. They give you three solutions, each with a known pH, and you're supposed to hold the calibration for five seconds while dipping it in each, in the order they suggest. The problem for me is that, when I do this, it tries to calibrate at 6.86 every time, rather than switching to 4 and 9.18 the two subsequent times I hold the button.I've therefore only calibrated this with the 6.86 solution. It should at least work as a rough guide as to whether a solution is acidic or not.

Out of the box I couldn't get this meter to read less than 8.7 with distilled water (checked with a calibrated meter).Even following the calibration steps with the provided powders made no difference.Could be faulty, or perhaps it's a question of not buying too cheap.