ExStik pH tester features a flat pH sensor making it ideal for testing semisolids and surfaces. Flat surface also reduces the chance of accidental breakage of the electrode tip—perfect for rugged field use! Built-in smart chip simplifies calibration and error diagnosis. CAL alert notifies you when it is time to recalibrate ensuring accurate readings. Renew indicator tells you when it is time to replace the electrode. Built-in memory recalls up to 15 sequentially tagged readings. LCD simultaneously shows pH and temperature readings, plus an analog bar graph of pH values lets you view reading trends. Waterproof tester floats in water.