I tested it for five stars but I don't have anything that compares. It has instructions for calibrating with distilled water and it was accurate. Very easy to use. I'm glad I have it. Use for winemaking.
Digital PH Meter Tester - Tiaoyeer Water Quality Tester With ATC, 0.01PH High Accuracy, 0.00-14.00 Measurement Range, 0.01 Resolution For Drinking Water, Aquarium, Swimming Pools, Hydroponic
8 Review
Efficiently Test Your Antifreeze And Battery Acid With A 3-In-1 Refractometer
18 Review
TDS water quality tester - TDS water hardness meter (portable digital salt meter for water analysis)
9 Review
Portable digital multimeter with sound continuity and thermocouple (electric tester) LTX DT-838
7 Review