VLF means Really Reduced Frequency and is similar know-how Utilized in detectors developed for cash, jewelry, and relics. VLF detectors broadcast at frequencies measured in kilohertz ranging from three kHz to 70 kHz. Listed below are five main reasons why you could possibly decide on a VLF about a PI http://opensource.platon.org/forum/projects/viewtopic.php?p=12846136#12846136