MH310 portable Hardness tester 1.Hardness Scale:HL,HB,HRB,HRC,HRA,HV,HS ... LCD,128*64 dots MH310 portable Hardness testerTechnical Specifications:Error and repeatability of displayed value:No.Type of impact deviceHardness value ... (57.5±0.5) mm, diameter is 30mm.Battery pack: 6V NI-MH Battery charger: 9V/500mAContinuous working period: about 150 hours(With ...