Device i.e. seed counting sensor, for use with e.g. pneumatic valve machine, has slot with chamfer on its annular area with respect to flow direction of small particles, where slot exhibits width between one millimeter and two millimeters

摘要

The device has a housing (14) with a measuring chamber (15) in which seeds are passed. A light emitter e.g. light source, and a light detector e.g. line scan camera and charge coupled device line, are arranged at distance to a conveyor pipe. An annular slot (17) is arranged in a wall of the pipe and is subjected with air pressure higher than air pressure prevailing in the pipe. The slot has a rounded circulating chamfer (33) on its annular area (31) with respect to flow direction of small particles. The slot exhibits width between 1 millimeter and 2 millimeters i.e. 1.5 millimeters.