Today, there are many metal detectors that have different models with different uses. In this text, we want to compare two metal detectors, PI and VLF.
VLF metal detectors
Usually, these types of metal detectors are very light and compact and have a small disk of 25 cm in size. In these metal detectors, the depth of exploration in the ground is less than one meter and it has low depth penetration power.
These types of metal detectors (VLF) are also called recreational metal detectors. Such devices are mostly used to find metal on the surface of the earth. It should be noted that these devices have a digital display and have a resolution of 80%. These devices can only separate ferrous metals from other objects with a suitable resolution.
Advantages of VLF metal detector
This type of device uses a strong separation system that has the power to separate metals such as gold, copper and silver.
Also, VLF metal detectors consume less battery than other systems. Another advantage of these devices is their greater sensitivity to non-ferrous metals. Similarly, the high power in detecting the exact point is one of the other advantages of this metal detector.
Disadvantages of VLF metal detectors
The depth of exploration of this type of metal detectors is much less than pulsed metal detectors, they cannot work in special environmental conditions and the depth-finding ability of these devices drops drastically.
Also, this device shows high sensitivity to minerals and minerals in the soil. Another disadvantage of these metal detectors is that they do not have the ability to travel underwater and cannot explore well.
Pulsed PI metal detectors
Today, this type of metal detector is one of the most widely used metal detectors among explorers. In the technology of these metal detectors, two separate coils are not needed. In these devices, one coil with different sizes is used as transmitter and receiver.
In this technology, current pulses are shown through a charging coil. Each pulse has a mixed magnetic field, when the pulse is turned off, these magnetic fields will also disappear, and this causes a steep amplitude in the coil, and this causes a current from the coil, which is called (back emf) has it.
When metallic objects are coiled around the magnetic field, the pulse creates an opposing magnetic field in them. Then the generated wave is amplified by the pre-amplifier and transferred to the audio part of the device.
Advantages of pulsed metal detectors
One of the important points that is very noticeable in these types of devices is that they are not sensitive to the minerals in the ground. Since Iran’s soil has many pollutions, this device does not show sensitivity to these pollutions.
Also, one of the other advantages of these devices is their higher depth compared to VLF devices. It should be noted that pulsed metal detectors can have a half depth of 3 to 3 meters, which is much more compared to VLF devices. Of course, in the catalogs of the pulse devices, the depth of drilling up to 8 meters is also written, which can be said that this issue was created only to sell more and better products by profit-seeking people and is considered the only way to abuse people.
Disadvantages of pulsed metal detectors
These devices have a lower sensitivity to precious metals such as gold. And their resolution is much weaker than other samples. One of the disadvantages of pulse metal detectors, which is considered very important, is its excessive battery consumption.
