Feature:Lock function: makes it easy to read and record, press HOLD button then remove from test solution.The instrument displays the TDS value at the factory. To measure the conductivity of the solution, please touch the SHIFT button and the meter will automatically switch;The meter has automatic temperature compensation in the measurement mode;Touch the SHIFT button twice in a row, the Celsius degree is converted to Celsius, and the instrument defaults to Celsius;Operation:1: Remove the electrode protective cap before use2:Press the ON/OFF button, and immerse the meter into the solution. (The solution should not over the immersion line)3: After the numerical display is steady, press the HOLD button and take it out of the solution for checking the result4: Wipe clean the electrode after using, turn off the meter and replace the protective capUse range:Check whether the water quality of tap water, purified water and mineral water meets the drinking water standards set by the state: tap water below 300 PPM, pure water below 50 PPM (national standard), and mineral water between 100-200 PPM.This product is also suitable for soilless cultivation. It needs a conductivity meter to measure the ion content of nutrient solution. This product can be used for nutrient solution concentration measurement. The value of the second measurement can be subtracted. The method is to measure the TDS value of the tap water first, then add the nutrient solution, and measure the value, and the value of the second subtraction is the value obtained.Specification:Measurement Range: Conductivity: 0 - 9990 μs/cm TDS: 0 - 5000 ppm (parts per million) Degrees Celsius: 0.1 - 80.0°CFahrenheit: 32.0 - 176.0°FAccuracy: ± 2%Net weight: 55gSize: 154 x 30 x 14(mm)Battery: 1x3V CR2032 ( No included )Color: BluePackage includes:1 x TDS & EC Meter