Portable soil hardness tester 1.Test hardness 2.Big LCD screen 3.large memory ... storage function 4.Data output function Portable soil hardness tester Functional features1High accuracy and high resolution: large screen LCD display ... , Power, charging power supply: 220V/AC, Continuous operating time of battery,6~8 hours7, Stability, temperature drift: 0.2uV/°C(0 ...