VLF stands for Very Minimal Frequency and is identical technological innovation used in detectors constructed for coins, jewellery, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from 3 kHz to 70 kHz. Here's 5 explanations why you would possibly pick a VLF around a PI a golden https://zenwriting.net/starc13/extreme-conditions-metal-and-gold-detectors