... ,CE,ROHS 4:manufacture,fair price DC linear scaleDC10 Universal linear scale resolution: 10um, 5um, 1um, 0 ... )Bench marks:the grating period:20um optical linear scaleGrating system:transmission infrared optical measuing system. ... Glass precision measuring grating is adopted for the Linear Encoder as measuring benchmark to ensure high precision ... 1 or 5 um measure length 500-1000mm linear optical endocer