Optics 3

Spectrometer Standard P-7055
Good for many quantitative light experiments by students at Junior level, reading to 0.10 (6 minutes of arc) The base combined with the collimator tube support, carries arc rotating telescope arm. The collimator and telescope tubes are one piece casting of light alloy, focusing by friction drive rack and pinion, 170 mm dia circular scale reading 0.10 but 0.050 can be estimated due to larger width of scale.
Spectrometer Intermediate P-7060
Its optical system and features are equivalent to those of advanced model making it still able for senior students to do many quantitative experiments.
Substantial iron casted base with leveling screws, protected graduated disc 150 mm diameter, fixed to table, double ended single vernier reading to 1 minute of arc attached to telescope.
Sodium lamp with transformer & housing P-7065
Comprises a 35 W sodium discharge tube, housed in metal shield with a 25 mm diameter aperture and mounted by means of a bosshead on an alloy rod at the control box. The transformer and ONOFF switch are mounted in the control box. For 222 V A.C., 50 Hz. supplies