Arc 7 Arc 7L DISTANCE MEASUREMENT(GOOD WEATHER) single prism   5.0km Mini prism   3.0km reflectorless 600m                                                 800m accuracy with prism: 2mm 2ppm; without prism: 3mm 2ppm reading max: 99999999.999  min: 0.1mm measuring time fine: 0.3s; tracking: 0.1s atmospheric refraction & earth curvation correction T-P sensor, Auto Detect and Correct prism constant manual input, auto correction ANGLE MEASUREMENT measuring method absolute encoding diameter of raster disk 79mm minimum reading 0.1″/1”/5” selectable accuracy 2”   detection method horizontal: dual      vertical: dual TELESCOPE image erect tube length 154mm effective aperture Telescope: 45mm;  EDM: 50mm magnification 30X field of view 1°30’ resolviong power 3” min. focusing distance 1m AUTO VERTICAL COMPENSATOR system 2-axis liquid-electric working range ±3’ accuracy 1” LEVEL plate vial 30”/2mm circular vial 8’/2mm OPTICAL PLUMMET image erect magnification 3X focusing range 0.5m ~ ∞ field of view 5° Laser plummet optional DISPLAY type 3.5 inches LCD, 640X480 touch screen Windows CE6.0 operation system ON-BOARD BATTERY type rechargeable Lithium battery voltage DC 7.4V, 3100mAh charging time 2 hours operating time 10 hours DATA STORAGE Internal memory 128MB DDR, 512MB NAND Flash SD card Max. 32G Communication port RS-232 port(6 pin), Mini USB, SD card, Bluetooth DIMENSION & WEIGHT dimension 200 X 190 X 350mm weight with battery 6.0kg