A system, method and apparatus may comprise a wafer having a plurality of spiral test structures located on the kerf of the wafer. The spiral test structure may comprise a spiral connected at either end by a capacitor to allow the spiral test structure to resonate. The spiral structures may be located on a first metal layer or on multiple metal layers. The system may further incorporate a test apparatus having a frequency transmitter and a receiver. The test apparatus may be a sensing spiral which may be placed over the spiral test structures. A controller may provide a range of frequencies to the test apparatus and receiving the resonant frequencies from the test apparatus. The resonant frequencies will be seen as reductions in signal response at the test apparatus.