In professional metal detecting area, VLF and PI metal detector are adopted to work together with each other to adapt to the versatile environment condition. PI metal detector is not good at discrimination. So such model is frequently used by many treasure hunters during in their searching for underground buried treasure. The magnetic field of target will strengthen the “echo” of reflection pulse to make it last longer. Here . However, it is useful in areas where VLF metal detectors have difficulty in such as in salt water area. Both the models are applicable in gold detecting. Which to choose will largely depends on the budget you set for your metal detecting. Surely there are other kind of metal detector called BFO, which is little used by treasure hunter because of its comparatively inferior accuracy and capacity. In comparison, VLF metal detector is better featured at the discrimination competence. In the market of metal detector, there are also a variety of PI metal detector models, differing with each other in terms of depth, function, quality and so on. It will last very short time like 30 micro seconds or so, then another pulse is sent to repeat the process. PI metal detector adopts PI technology which is to generate a short magnetic field by short pulse of electrical current sent through search coil wire. The working theory of PI metal detecting is a bit like that of echo. When the pulse ends, the polarity will reverse to cause another reflected current on the coil. Unlike VIF metal detectors, which have two coils as transmitter and receiver respectively, PI can use single coil to perform the functions of both as well as with other coils work together. Nowadays, metal detecting enthusiasts would select either a VLF metal detector or a PI metal detector, since most of the metal detectors fall within the scope of the two sorts of model. PI have better depth capacity too when used ground search detecting. VLF model metal detectors are more likely to detect smaller pieces of gold with the ability to differentiate trash from the target objects, and on the contrary, PI metal detectors are more suitable for gold object with larger size. VLF and PI metal detectors are designed to suit different application. The electro-magnetic pulses come with a deep penetration capability, which is not affected by the soil or water condition.PI metal detectors are known as the ideal equipment for great depth ground search and underground search, especially beach salt waterside metal detecting
