Abstract: An aspect of the present invention is to provide a Virtual light table that is an implied or virtual representation of two plans overlaid onto one another. Embodiments of the invention allow the output to be configured and or filtered to allow various display modes and image combinations, and since the comparison is computer generated all differences noted will be output as specified and the user can select an appropriate display mode to view what they wish to see. Another aspect of the invention is that users can select plan files to compare at any stage of the drawing as they wish, and they can do batch compare or select regions of interest on each plan and conform (scale and translate) one image to be overlaid as needed onto another. Preferred embodiments allow for many annotation applications to be used to markup a comparison image giving users the ability to choose the best application for their needs.

Abstract: A suction-air system of a textile machine, especially a rotor spinning machine, has at least one suction-air conduit, at least one spark sensor for detecting flying sparks within a measuring extent of the suction-air, the sensor including a measuring device with a sensing range at least partially overlapping the measuring extent, at least one electromagnetic wave receiver for generating an output signal when a spark enters the sensing range, and a driver and evaluation circuit for the measuring device. At least one source for generating electromagnetic waves is associated with the receiver and actuates a purposeful initiation of the spark sensor.