The invention is a method and apparatus for calibrating a gap sensing probe (12) in a refiner having first (76) and second (80) grinding plates facing each other and supported by respective first and second plate holders, each grinding plate having a face (78, 82) defining a grinding gap (86). ...http://www.google.es/patents/US5691636?utm_source=gb-gplus-sharePatente US5691636 - Probe assembly mounting for a grinding machine
