Abstract: The measurement of equivalent sphere illumination on a given task located in a lighted area is disclosed herein. This is accomplished by comparing a movably mounted task in the lighted area with the same task in a control area illuminated with sphere illumination. The task is viewed alternatively in the two areas in accordance with specific optical procedures to determine the equivalent sphere illumination on the task in the lighted area.

Abstract: An auxiliary assembly for use with an apparatus which raises and lowers a luminaire support ring along a support pole and which supports the ring during this movement is disclosed herein. The apparatus includes a main drive, a main cable connected to the drive and a plurality of secondary cables connecting the main cable and therefore the main drive to the luminaire support ring. The auxiliary assembly includes an auxiliary supporting arrangement connected with the main cable of the apparatus whereby to support the ring in the event there is a failure of either the main cable or the main drive to support the ring. This assembly also includes a device for automatically and substantially immediately sensing the presence of such a failure and for automatically providing a predetermined signal at substantially the moment of failure.