Device for measuring contamination of lubricant

摘要

In a lubricant contamination measuring device, an optical path gap is provided between a light source window at a light source side and a light receiving window at a light receiving element side. A lubricant having an amount of contaminant to be measured in accordance with a light transmittance is present in the optical path gap and the length of the optical path gap is selected to be shorter than a predetermined length. At least one of the light source and light receiving windows has a convex shape, and the center of the convex window is in contact with a surface of the other window. Thus, the amount of contaminant in the lubricant can be measured up to a high contamination range.