Instrument features: with numbers / character keys, built-in powerful RoadRunner software, simple operation; meet the special requirements of non-prism measurement operations, which, GPT-3102N without prisms mode measurement range up to 350m; unique Topcon compact pulsed laser technology makes optical system GPT-3102N series in non-prism mode uses only a laser; dual measurement mode operation is simple according to required field applications, requiring only simple one button operation to switch with / without prism mode measurement; alignments point guiding function; ample memory space for data storage, can store 24,000 observation points 24,000 coordinate points; particularly durable, dustproof to IP66 level; equipment, long-lasting battery (BT-52QA), operating time up to 10 hours; angle measurement accuracy: ± 2 "/ 5", the absolute angle measurement method without zero test. Telescope Length: 150mm Objective aperture: 45mm (EDM: 50mm) Magnification: 30 × Erect Field of view: 1 ° 30 'Resolution: 2.8 "Minimum focus: 1.3m distance measurement single prism: 2000m prism: 2700m Accuracy : ± (2mm +2 ppmD) mse ranging accuracy non-prism mode (diffuse surface), 1.5 ~ 2.5m: ± (10mm) m, s, e, 25m above: ± (10mm) m, s, e non-prism ultra- Long mode: ± (10mmm ± 10ppmxD) m, s, e prism long mode: ± (3mmm ± 2ppmxD) m, s, e the minimum reading Fine mode: 1mm/0.2mm Coarse measurement mode: 10mm/1mm tracking mode : 10mm accurate measurement time mode: 1mm approximately 1.2 seconds (first 3 seconds) Coarse measurement mode: Approximately 0.5 seconds (2.5 seconds for the first time) Tracking mode: approx 0.3 seconds (2.5 seconds for the first time) Angle measurement accuracy: 5 "angle measurement ways: absolute method of reading levels: H: right diameter Vertical: Single Path Minimum reading: 5 "/ 1" Measuring time: less than 0.3 seconds Display Display: 160 × 64 dot matrix graphic LCD with backlight, double sided Keyboard: 24 Function Key tilt compensator method: Liquid Type: biaxial compensation range: ± 3 'other batteries: Ni-MH battery performance Circular level: 10/2mm vial: 30/2mm Working temperature: -20 ℃ ~ +50 ℃ Use time: about 4.2 hours (angle and distance measurements), about 45 hours (angle measurement only