Abstract: A system for on line analysis of material samples in accordance with the invention includes a grinding mill for comminuting sample material to output comminuted sample material; an analyzer unit for performing the on line analysis of the outputted comminuted sample material and having a housing holding an optical system having a front glass with the optical system performing the on line analysis of the outputted comminuted sample material, and a receiving chamber for receiving the outputted comminuted sample material from the grinding mill; and a mechanism for moving the housing relative to the receiving chamber between a first position at which the front glass closes a wall opening into the receiving chamber and a second position at which the front glass is cleaned by a cleaning mechanism.

Abstract: With the present invention, the NIR-technique is utilized for a fully automatic on-line analyzing of successive samples, viz. with the use of a test chamber which is built together with the optical unit and is open towards this unit through a restricted side opening. The test chamber has a volume which is much larger than that of the known test cups, whereby the remnant-pollution of the following sample can be kept at an acceptable low level, without the test chamber having to be totally cleaned each time. A particularly critical area, however, is the material area just next to the optical unit, and remnants at this place must by necessity be removed.