The Mullard 61SV is photoconductive cell operating in the infra-red region of the spectrum between 2.2 and 3.5 μm. It is a lead sulphide detector for use at room temperature. The end window is delicate and should never be touched.
The base pins.
The end window - should not have been subjected to the studio flash.
The warning notice included in the plain card box.
The end window envelope is 20 mm in diameter and, including the base pins, is 40 mm tall.