Contactless object presence and position detection - involves measurement of fluid overpressure using sensitive nozzle arrangement

摘要

A method is used for contactless detection of the presence and then the position of an object of small dimensions, e.g. a fibre, in a volume bounded by two opposite flat walls. The method is designed for increased sensitivity and reduced energy of the fluid used. Two nozzles project fluid into the vol. and the excess pressure caused by the object is measured. The volume height is little larger than the known cross-section of the object so that it resembles a flat two-dimensional space. The approximately two-dimensional nozzles (7, 7b) inject flat fluid flow into the volume plane. The flows run together at a point near the approximate object location where a press, pick-off opening is positioned.