4 in 1 Digital PH Meter Tester: PH meter is designed with 4 in 1 function that can be measured PH / TDS / EC / TEMPERATURE simultaneously with high accuracy and quickly. Omnidirectional measurement to ensure the health of water quality. The digital pH meters have reliable quality, durable ABS material IP 67 waterproof, ergonomic pocket size, best price, all these make it your FIRST water quality tester. ±0.01 pH Measurement Accuracy: With high sensitivity glass probe, the full measuring range of the pool water test is 0-14pH, with a resolution of 0.01 pH. And the pool pH tester uses a 3-point calibration method, calibrating the electrode to pH 4.00, pH 6.86, and pH 9.18 solutions to ensure the accuracy of your measurements. Easy to Calibrate: Simply immerse the electrode into the target solution, then press and hold the MODEL/CAL button for 5 seconds after the readings to stabilize (usually 5s to 10s), and the calibration will be done automatically. A large LCD backlit screen and dual