SPECTROMETER, ADVANCED, WITH DOUBLE VERNIER (0578) 177mm diameter circle, Allows readings to 30 seconds of arc. This instrument whilst robust enough for individual student use is also intended for more advanced work. The general finish of the apparatus is similar to that of the intermediate model. The instrument is mounted on a baseboard, which fits into a polished hardwood case. Scale: The 177mm diameter circle is fixed. and the table and telescope movements are completely independent of each other. Both movements can be read to 30 seconds of arc by means of double ended vernier. Both rotations have fine adjustment screws. and release of a clamping screw enables coarse adjustment to be made by hand. Mounted on fixed pillar and fitted with 178mm focus achromatic objective. 32mm clear aperture. A unilaterally adjustable slit. 6mm long is also fitted. Telescope Mounted on moveable pillar and fitted with 178mm focus achromatic objective. 32mm clear aperture. Also fitted is a 15 x Ramsden eyepiece and a crossline graticule. Both the telescope and collimator have rack and pinion focusing. Means are provided for leveling the axes of both optical units and for squaring them to the axis of rotation. Prism Table: The table is marked with lines to assist placing the prism with respect to the table leveling screws, and has interchangeable clamping units for the prism and a diffraction grating. Standard Set of Accessories, supplied in case: Dense Flint Glass prism -1 No., Prism clamp - 1 No ., Diffraction grating holder -1 Nos, Watchmaker's eye glass -1 Nos, Tommy Bar / L Key for adjusting optical axis of tubes -1 Nos, Polished hardware case. Qty :