HI 98140 is a portable Calibration Check™ pH meter that utilizes HANNA’ s SMART electrode technology. SMART electrodes incorporate a chip, which stores the calibration data performed with a specific instrument. When the “ SMART” electrode is attached to the meter again, it is automatically recognized. This allows the operator to optimize time and efficiency with unsurpassed safety. It also avoids erroneous measurements taken in the event the pH electrode is substituted after calibration. Order Information: HI 98140 is supplied with HI 1618D pH electrode, HI 70004 pH 4.01 buffer solution sachet, HI 70007 pH 7.01 buffer solution sachet, HI 70000 electrode cleaning solution sachet, HI 700661 electrode cleaning solution sachet, batteries, instructions and hard carrying case.