The ORP11 is a cadmium sulphide photosensitive resistor. The later ORP12 was made as a glass cup sealed with plastic and having wire leads.

The active material is seen as dark. The substrate is showing in an interdigital pattern. This gives increased length to the resistive material.

The thin glass tube envelope is 16 mm in diameter and, excluding the special base pins, is 46 mm tall.

This exhibit was last updated on 09 June 2001