Polarizer and Analyzer (Polaroid)
This apparatus consists of two identical units, each provided with Polaroid disc mounted in a rotatable mount, with aperture of 25mm. Both rotatable mounts have a lever to add rotation and a pointer which traverses a 75mm diameter brass silvered scale divided into 360°×1. The size is universal and can be fitted to any size of collimator and telescope. To fit over the object end of telescope and collimator.
Polaroid Specifications :
Thickness : 0.1 mm
Type : Nitrocellulose Polymer
Aperture : 25mm
Least Count : 1°.