Three models, with following features in common. Difference noted against each model.
Base: A Heavy Cast iron base, with scratch resistance, oven-baked paint. Heaviness of base ensures stability.
Body: Streamlined to avoid cervices around fittings, where the paint could peel on the long run. Holding pillars for telescope and collimator of solid metal block to provide durability.
Scale: Main Scale, diameter 15cm, is divided 0-360 X ½°, and fixed to a table that also holds the telescope. Two venires readings up to 1 minute of arc, located 180° apart at opposite sides of the main scale. Both venires visible through two protective, acrylic windows. Release of a clamping screw allows independent, rotation through fine adjustment screws for telescope and vernier scale. The scale and vernier have fine, granular finish for easy read ability.
Telescope: Mounted on a moveable pillar, with a fine adjustment screw, locking screw, axis adjustment. The achromatic objective is of focal length 17.8cm. Ramsden eyepiece 15 X with crossline graticule. With rack and pinion focussing for both objective and eyepiece.
Collimator: With achromatic objective of focal length 17.8cm. Rack and pinion focusing. Adjustable, 6mm slit is made of stainless steel.
Prism Table: Marked with grooved lines to assist positioning of prism in relation to the leveling screws. With interchangeable clamping units for the prism and diffraction grating. Electrostatically painted with matte black powder coating that is long lasting.
Spectrometers supplied with prism clamp, grating, holder coating that is long lasting.
Spectrometers supplied with prism clamp, grating, holder, magnifier lens, and tommy bar.
A.) Spectrometer with leveling screws.
Objective lenses of diameter 25mm, aperture 24mm.
B.) Standard Spectrometer
Solid base instead of leveling screws.
Objective lenses of diameter 28mm, aperture 26mm.
C.) Improved, Standard Spectrometer
As 1358B, but with objective lenses of diameter 32mm, aperture 30mm