Multi-element infra red sensors

A multi-element infra-red sensor comprising a glass Dewar tube having a tubular glass core open at one end and closed by a metallic plug at the other and a jacket surrounding the core with a space therebetween, said space being evacuated, the jacket extending beyond the closed end of the core and having an infra-red transmitting window at its end beyond the closed end of the core, a printed circuit member on the closed end of the core, said member having a face toward said window and a pattern of electrically conductive leads printed on its said face including a generally central common lead, an array of infra-red sensing elements on said common lead in ohmic connection therewith, said pattern further comprising a plurality of printed leads, one for each sensing element, radiating out toward the margin of said member from points adjacent but spaced from said common lead and having their outer ends spaced at intervals around said margin, electrical interconnections between said sensing elements and the inner ends of said radiating printed leads, and means extending longitudinally of the core from the outer ends of said radiating printed leads and from said common lead for interconnecting each sensing element in an electrical circuit with terminals on the outside of the Dewar tube.