Let X be a set and Ï a Ï-algebra over X. 1  A function Î¼ from Ï to the extended real number line is called a measure if it satisfies the following properties: 2  Non-negativity: For all E in Ï: Î¼(E) â¥ 0. 3  Null empty set: Î¼(â) = 0.
Contact wipe is an action designed into a contact so that the contact motion exceeds the initial electrical contact touch point. Using a flexible contact arm causes the contact surface to wipe against its counterpart as the arm bends slightly.
Counter-flashing (or cover flashing, cap flashing) is a term used when there are two parallel pieces of flashing employed together such as on a chimney, where the counter-flashing is built into the chimney and overlaps a replaceable piece of base flashing.