... under the dark environment;6. USB interface;7. Low-power design, auto sleep, auto shutdown; 8. Fully enclosed ... LCD with back-lightDisplay FunctionsImpact direction, Date, Time, Battery power status, Memory reference, Hardness scale, Hardness value, Average value, Max ... times, operating instructionAccuracyWithin ±0.5% (at HLD=800)Hardness Parameter HL,HRC,HRB,HV,HB,HSMeasuring Range/MaterialsSee ...