Mohs scale of mineral hardness incorporates additional substances that may fall between levels: Comparison between hardness (Mohs) and hardness (Vickers): Mohs scale of mineral hardness The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. Created in 1812 by German geologist and mineralogist Friedrich Mohs, it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by seeing which minerals can visibly scratch others is, however, of great antiquity, having been mentioned by Theophrastus in his treatise
Roll hardness tester important parameters when deciding whether a paper roll is good or bad. A roll that is wound too softly can go out of round when handled. A roll that is wound too hard, on the other hand, can crack during transportation. These variations are difficult to detect. Above all, it is typically the variation in hardness across a given roll that relates most directly to such converting issues with soft edges being perhaps the biggest contributor. Roll hardness tester A roll hardness tester is a device to measure the roll hardness, hardness profile and hardness variation of paper rolls. In