Mohs scale of mineral hardness testing the resilience of certain flat panel display components (such as cover glass for LCDs or encapsulation for OLEDs). The Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly. The samples of matter used by Mohs are all different minerals. Minerals are chemically pure solids found in nature. Rocks are made up of one or more minerals. As the hardest known naturally occurring substance when the scale was designed, diamonds are at the top of the scale. The hardness of a material is measured against the scale by
Ringelmann scale are equivalent to an opacity of 0, 20, 40, 60, 80 and 100. Some agencies issue cards that can be compared to the smoke while others use apps on phones. Ringelmann scale The Ringelmann scale is a scale for measuring the apparent density or opacity of Smoke. It was developed by a French professor of agricultural engineering Maximilien Ringelmann of La Station d'Essais de Machines in Paris in 1888. Ringelmann also discovered what is now called the Ringelmann effect. The scale is has a 5 levels of density inferred from a grid of black lines on a white surface which,