Significance and Use The primary purpose of the PMA test is to
determine the presence of mechanical damage, wear through, and
other gross defects in the coating. Most metallic coatings are
intended to be protective, and the presence of gross defects
indicates a serious reduction of such protection. The protection
afforded by well applied coatings may be diminished by improper
handling following plating or as a result of wear or mechanical
damage during testing or while in service. The PMA test can
serve to indicate the existence of such damage. This test is
used to detect underplate and substrate metal exposed through
normal wear during relative motions (mating of electrical
contacts) or through mechanical damage. As such, it is a
sensitive pass/fail test and, if properly performed, will
rapidly detect wear through to base metals or scratches that
enter the base metal layers. This test is relatively insensitive
to small pores. It is not designed to be a general porosity test
and shall not be used as such. The