Fast and accurate readings - just turn it on, dip it in liquid and get the reading without having to mess with color charts or test strips; the large digital display makes the display easy to read. Automatic Calibration - No adjustment with a screwdriver is required, just complete the calibration with the auto calibration button and the included powder buffer. ATC Function - Due to the variability of factors, the temperature of the test objects may have been slightly different, which may result in inaccurate readings. The ATC function can automatically compensate the temperature of test objects, thus avoiding inaccuracies in readings. Portable Design - Thanks to the compact pen pouch and carrying case, you can easily put it in your pocket and take it anywhere. Application - Water testing in swimming pools, ponds, spas, laboratory testing, food processing, hydroponics, aquaculture and even home aquarium. Product Description Ph Meter Calibration Methods: 1. Add 6.86 to 250ml of water to