HM meter measures electrical conductivity (EC), total dissolved solids (TDS) and temperature. Three different calibration options (KCl, 442TM, NaCl), each with its own non-linear conversion factor. Automatic Temperature Compensation (ATC) using three temperature coefficients. Waterproof housing with digital calibration (push button). Measurement Range: 0–9990 µS; 0–8560 ppm. Auto-off, data-hold functions and low battery indicator. Display: large and easy-to-read LCD screen includes simultaneous temperature reading. Factory calibrated with a 1413 µS solution. The meter can be recalibrated with digital calibration using the push buttons, no screwdriver needed. Includes a cap, batteries and lanyard.