amtra Digital Conductivity Tester is an electronic tester that allows the rapid and precise determination of the conductivity of the water (EC inS and TDS in ppm) of your aquarium. Practicalpenshape to be carried and used anywhere. Possibility of automatic recalibration and temperature compensation are among the main advantages of this device suitable for both beginners and expert aquarists.amtra Digital Conductivity Tester+ practical digital meter for measuring the conductivity of water (EC inS and TDS in ppm)+ integrated automatic temperature compensation ATC system+ possibility of re-calibration+ auto shutdown after a few minutes of inactivity+ included hard case for safe storage+ EC measurement scale: 0-9990S/TDS: 0-9990ppm+ 0.1-80.0C / 32.0-176.0FInstructions for Use amtra Digital Conductivity Tester:Remove the protective cover of the electrode. Press ON/OFF and insert the electrode into the solution to be tested. When the numbers on the display are stable, press HOLD,