VLF stands for Extremely Small Frequency and is similar engineering Utilized in detectors developed for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz ranging from three kHz to 70 kHz. Listed below are 5 explanation why you would possibly select a VLF around a PI The http://opensource.platon.org/forum/projects/viewtopic.php?p=12846162#12846162