The phenomenon of positive spiking in Direct Current(DC) ripple is not well understood by most cathodic protection field personnel. This study was an attempt to verify the exislence of positive spiking in DC ripple, and
possible results. During the project one hundred cathodic protection (CP) rectifiers were observed and oscilloscope waveforms recorded in Tyler, TX. ln Bishop, TX stainless steel pins were utilized to observe voltage and current movement through the ground, again an oscilloscope was used to observe and record waveforms. Finally a laboratory type experiment was developed using steel nails as anodes and cathodes to observe different
corrosion rates by different current sources. An existing CP rectifier installation was employed, to provide both “filtered” and “unfilterd” DC protective currents, and a wet cell battery to provide pure DC protective currents. These studies indicate corrosion rates may be affected by positive spiking.
Keywords: cathodic protection, waveform, Alternating Current, Direct Current, DC ripple, oscilloscope, rectifier