0414

Maker	TOPCON (Japan)
Model	GTS-2 10
Serial Number	B45056
Dimensions	(Without carrying handle and clip-on battery pack) telescope length 169 mm, Height 380 mm, Width 195 mm
Image
Description	This GTS-2 10 semi-electronic tacheometer is a combination of an electronic distance meter (EDM) and an optical scale-reading theodolite which has been consolidated into a single very compact and light-weight unit. The axis of the infrared light beam and the optical line of sight are in coincidence, thus making possible accurate electronic distance measurements and angular measurements at one pointing of the instrument. Distance measurements start automatically, after pointing to a prism, with the return signal level optimised by an automatic level control system. The measured distance is displayed by light-emitting diodes (LED's) in a digital readout, directly over the telescope's eyepiece. The angles are read optically. The circles are numbered in one degree divisions. The directions and zenith angles are read in the reading telescope of the optical micrometer, from left to right, to 10 seconds of arc. In spite of its compact size, the GTS-2 can measure distances up to 1.4 km to a single prism and 2.0 km to triple prisms, under ideal atmospheric conditions. The weight of the instrument is 6 kg (without the carrying handle and the clip-on battery pack). The instrument features an accurate and fast responding automatic vertical circle indexing system. The range and setting accuracy of this system is ±5' and ±0.25", respectively. The sensitivity of the circular level is 10'/2mm and the sensitivity of the plate level is 30"/2mm. The distance measurement precision is in the order of about ±(5 mm + 5 ppm). The measurement time in the FINE mode for long distances can take as long as 7 s.
History & comments	This is the first mass-produced electronic tacheometer from Topcon with a balanced telescope.
Conservation	Plastic carrying case (L 536 mm, W 375 mm, H 240 mm).
Condition	Good condition
Remarks	The weights of instrument and carrying case are 6.0 kg and 5.5 kg respectively. Erect telescope image 30x telescope magnification The vertical and horizontal clamps and tangent screws are located close to each other on the same side for convenience. Catalogued by F. Pall
Dates	Catalogued in 2000.