A process of providing a gradient field includes providing a pair of opposing magnets and associated magnet poles, which are divided into zones. The pivot pin is pivotally connected to the first hinge member to provide pivotal movement of an external vehicle closure member about a horizontal pivot axis between a closed position and an open position. The system may be installed in an aircraft. An additional reduction in the test time is achieved by using comparators with upper and lower limit reference signals and a pass-fail logic test. After oxidation, the oxide pattern can be obtained and it is easy by etching process. When the seat protector covers a hot car set, a person may safely sit upon the seating surface without the seating surface burning his or her skin.