DIN 51821-1
DIN 51821-1 Testing of lubricants - Test using the FAG roller bearing grease testing apparatus FE9 - Part 1: General working principles
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2016
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2016