Waterproof and chemically resistant, HI 993301 has been designed to meet the grower' s need for equipment suited to the aggressive environments found in agricultural and hydroponics applications. At startup, HI 993301-01 performs a self-check to ensure proper working condition. This monitor from HANNA has a backlit LCD and displays instantaneous readings of both EC or TDS and temperature— even from a distance. This instrument features a stability indicator that prompts the user when to take the reading. For manual recording purposes, readings can be frozen on the LCD display by pressing the HOLD button. Calibration and temperature compensation are automatic, while the EC/ TDS conversion factor and temperature coefficient factor ( ² ) are user adjustable for application specific measurements. Order Information: HI 993301-01 ( 115V) and HI 993301-02 ( 230V) is supplied with HI 7630 conductivity probe, HI 70031 1413 µ S/ cm calibration solution sachet, 12 VDC adapter and Instructions.