Thin film resistors have a metallic film that is vacuum deposited on an insulating substrate. Thick film resistors are produced by firing a special paste, which is a mixture of glass and metal oxides, onto the substrate. Thin film is more accurate, has a better temperature coefficient and is...
you should test using different Opening pressure valve testing machine, vacuum valve testing machine, diaphragm seal testing machine and torque tester, these radiator caps are manufactured as per the specifications.