Maker

Wild, Heerbrugg, Switzerland

Model

GDR 31

Serial Number

n/a

Dimensions

160 x 137 x 80 mm

Image

Description

This rectangular EDM reflector was designed for the electronic distance meter WILD DI3 (telescope mounted) Distomat. The centre of the reflector sits 38 mm above the tilting axis (as the Wild DI3 sits 38 mm above the telescope axis (line of sight) of thehost theodolite. The froint face of the prism is 94 x 46 mm. The rectangular shape is required because the front lenses of the transmitter and receiver of the DI3 are side-by-side and have each a diameter of 35 mm.

The range of the original DI3 to this prism was given as 300 m minimum in 1973 (and 400 m in 1975). For longer distances ( about 600 m in 1975), the triple-prism reflector GDR11 was available (see item 0420).

The host theodolite is pointed to the yellow triangles underneath the prism before any distance measurement. The back faces of the glass prism of the GDR31 are NOT coated and can/should be cleaned by the user.

For mounting on a tribrach, the GDR31 requires a reflector carrier GRT10, for example.

Weight 1.5 kg

History & comments

Donated by the NSW Department of Main Roads (DMR)

Conservation

no case or satchel

Condition

some paint damage

Remarks

In the back, the reflector is engraved 'DMR 0128'

Dates

Catalogued by J. M. Rüeger in 2012. Photos by J. M. Rüeger.