Abstract: The invention comprises a passive infrared intrusion detector including a lamp for locating the zones being protected by the detector. The detector includes a heat sensor, a lens system for receiving and focusing the body heat of an intruder on the heat sensor, and electrical circuitry responsive to the heat sensor for actuating an alarm or detection signal when the body heat of an intruder is detected.The zone locator lamp is positioned near the heat sensor and its light passes through a lens in the general direction of a zone to be protected. The light parallels a portion of radiation which is focused on the heat sensor by another lens. If the light can be observed from a given position in front of the detector, that position is in a zone being observed by the detector and body heat radiated from that zone will be focused on the heat sensor. Thus, zones protected by the intrusion detector can be established by adjusting the position of the detector until light from the zone locator lamp is observed.

Abstract: An improvement in a photoelectric intrusion detector unit of the type designed to resemble a duplex electrical outlet. An angled mirror and a collimating lens are supported on a common mount which is rotatable about an axis of rotation which is angularly displaced from the optical axis of the lens but passes through its focal point. The optical axis of the lens describes a conical surface about the axis of rotation.

Abstract: An improved arrangement for orientating an apparatus which is adapted to transmit, receive or relay electromagnetic or acoustical energy is described. The apparatus includes a housing and a housing positioning means and a housing mounting means are provided for mounting the housing to a support body. The housing includes a housing member having an elongated surface which is adapted to be positioned adjacent a surface of the support body. The housing surface has a cross-section configuration for providing a first plurality of alternative orientations for the apparatus while the housing positioning means is adapted to be located between, and in contact with, the housing member surface and the support body and to cooperate with the housing member surface to provide a second plurality of alternative apparatus orientations.