Recently I was teaching an NFPA 70E electrical safety class and we were discussing the importance of establishing an electrical safe work condition. I showed the class a Santronics low voltage detector. This is a wonderful device (commonly used by OSHA compliance officers) for general troubleshooting but NOT to confirm an electrical safe work condition. As part of my demonstration, my low voltage detector did not light up when inserted into a 120-volt receptacle. I informed the class this is part of the problem utilizing such a unit for verification – the unit may have dead batteries; be damaged; or simply in need of replacement – as mine was. A qualified person may erroneously assume the failure for the unit to indicate the presence of electricity as an electrical safe work condition – a potentially fatal mistake. This is also true with tic-tracers. Both of these are great as a troubleshooting tool – but nothing more. For proper verification a meter with a readout is required clearly indicating 0 volts. Also, the meter must be verified for proper operation with a know voltage prior to and immediately after the verification.