FEATURES: Measures electrical conductivity (EC), total dissolved solids (TDS). Excellent for nutrient testing. Four scales: EC: µS, mS; TDS: ppm, 0.5 (NaCl) & 0.7 (442™). Automatic Temperature Compensation (ATC). Water resistant. Digital Calibration (push button) to any point within the meter’s range. Auto-off function, data-hold function and low-battery indicator. Display: large and easy-to-read LCD screen includes simultaneous temperature reading.  Factory Calibrated: The COM-80 meter is calibrated with a 1413 µS solution. Includes a protective cap and batteries. It is ideal for testing applications such as hydroponics & gardening, pools & spas, aquariums & reef tanks, water ionizers, drinking water and more.