This is a microscope designed for viewing the scattered light imaged onto the plane of the entrance pinhole to the Interferometer. By thus viewing from behind the input pinhole the scattering optics may be adjusted to give optimum collection of the scattered light. Also enables the reference beam to be accurately aligned with the measurement beam.

Move the lever on the side down to view and up to measure.

Scattering spot focussed correctly on centre of 150mm pinhole	Scattering spot Incorrectly adjusted