One way to test for pinholes or cracks in a cable's insulation is to immrse it in water. Connect your hipot tester high side to the cable's conductor and the low side to an electrode immersed in the water. We have also used that technique to check the encapsulation of photovoltaic panels.
I kike the idea of safety, but exactly how would a hipot test detect holes in the outside insulation of, say, a shielded cable? It seems the cable must be wrapped in foil, or passed through a conductive and compliant 'doughnut' while 'hot' to do this.
Replay available now: A handful of emerging network technologies are competing to be the preferred wide-area connection for the Internet of Things. All claim lower costs and power use than cellular but none have wide deployment yet. Listen in as proponents of leading contenders make their case to be the metro or national IoT network of the future. Rick Merritt, EE Times Silicon Valley Bureau Chief, moderators this discussion. Join in and ask his guests questions.