Telescope Image Erect image Magnification 30x Effective aperture 45mm Resolving Power 3� Field of view 130 Minimum 1.4m Stadia Ratio 100 Stadia Constant 0 Sight Distance Precision 0.40% L Tube Length 157mm Angle Measurement Angle Measurement Mode Photoelectric detection by incremental decoder Dia of circle ( vertical, horizontal) 79mm Mode detection Horizontal angle: dual; Vertical angle: ( single) Measurement unit 360o / 400gon/ 6400mil ( available to choose) Levelling vial Sensitivity of plate vial ( / 2mm) 30� / 2mm Sensitivity of circular vial 8’ / 2m Vertical compensatory System Liquid condenser Working range ± 3� Precision 1� Optical Plummet Image Erect Image Magnification 3x Focusing range 0.5~ µ Field of view 5o Display Type LCD, Double line, line segment Data input/ output Data interface RS-232C On-board battery Power source Rechargeable Ni-H battery Voltage DC6V Operating time 8h Working environment Working temperature -20o~ + 45o Instrument Dimension / Weight 160x150x330mm / 5.2kg