Patent ID: 9205464
Filing Date: 2015-12-08
Classification: B08B,G01N,G02B

Abstract:
1. An arrangement for mechanically cleaning of at least one transparent surface of an optical instrument inside an instrument container containing liquid to be measured, the instrument container having a circular or elliptical cross-section that allows rotating motion of the liquid around a rotation axis, the optical instrument being placed in an aperture in a wall of the instrument container, wherein the instrument container is at least partially filled with cleaning media, wherein the cleaning media comprises separate moving objects, wherein at least one of material, shape and size of the moving objects is selected appropriate to the nature of the surface to be kept clean, the instrument container being provided with fluid supply means for supplying fluid to drive the liquid and cleaning media to rotating motion inside the instrument container, the cleaning media forming an essentially uniform bed during rotation of the moving objects with the cleaning media, whereby the cleaning media wipes clean the at least one transparent surface being exposed to cleaning media through the instrument aperture, wherein the cleaning media has a different density than a filling liquid such that the cleaning media can settle to either a bottom or a top of the instrument container for a limited period of time when stopping the forcing influx, and that an amount of the cleaning media and the position of the aperture are arranged such that there exists a safety area between the settled cleaning media and the aperture, providing safety tolerance for the cleaning media not to cover the aperture during the measurement phase.