Patent ID: 6204507
Filing Date: 2001-03-20
Classification: D21G,G01B

Abstract:
An apparatus for checking weights per unit area during production of a sheet of material having first and second sides opposite one another, comprising:a source of radiation disposed on one side of a path of travel of the sheet of material to irradiate a width of said first side of the sheet of material with a linear distribution of radiation;a detector assembly disposed on another side of said path of travel of the sheet of material and having a common housing with a cover and a plurality of measurement chambers disposed in alignment with said source of radiation and to extend over the width of the sheet of material facing said second side of the sheet of material to receive radiation passing through the sheet of material, each of said measurement chambers being bounded by wall electrodes with a collector electrode therebetween;said measurement chambers being communicated to one another to permit joint evacuation and filling with ionizable gas; andsaid cover defining individual radiation entry windows respectively for each of said measurement chambers.