Metal Detector Technology

Metal Detector Technology

Metal detector technology has improved tremendously over the years and plays an important role in our lives, ranging from security to food, mining, and treasure seeking.

Over time, people are becoming more interested in metal detection. They enjoy searching for valuable items as a hobby and passion, not just for money.

As technology improves day by day, the number of people taking an interest in metal detection is also increasing.

In this article, we will give you important information about metal detector technology. This will help you choose the right technology when you buy a new detector.

Categories of Metal Detector Technologies

The major three technologies used are:

  • VLF Technology
  • Pulse Induction Technology
  • Ground Penetrating Radar Systems (GPR Systems) or Radar Technology

Very Low-Frequency Technology (VLF Technology)

VLF technology is the most common technology widely used in detectors. The majority of devices are based on VLF technology.

In the past, Beat Frequency Technology (BFO Technology) was used in old devices. But now it is completely obsolete due to the lack of many features such as discrimination. Mostly beginner and professional-level devices are equipped with this technology.

VLF technology devices are mostly used for coins and relics hunting. Some VLF devices are equipped with relatively high frequencies to detect gold nuggets.

VLF technology uses two coils: one coil sends the signal underneath the ground, and the other receives a signal from the target object.

The sender coil creates an electromagnetic field to detect the target. When the target is found, the receiver coil detects the field coming from the target and sends it to the control unit for further processing. VLF technology offers various options for frequencies such as:

Single Frequency:

The device operates at one frequency and is made to find certain targets like coins or relics.


In multi-frequency mode, your device has the option to work on 2 or 3 frequencies, but you can only select one frequency at a time. For example, your device can work on 5 kHz frequency, 10 kHz frequency, or 15 kHz frequency. It means it will be able to detect objects of 3 different sizes depending upon the frequency selected among these 3 frequencies.

To find the Best multi-frequency metal detectors

Simultaneous Multi-Frequency:

The device can work on all the available frequencies at the same time using multi-frequency mode. It means you don’t need to change the frequency again and again to detect target objects.

Pulse Induction Technology or PI Technology

This technology is basically used for treasure-seeking. Pulse induction technology has weaker discrimination power than VLF.

However, it has good depth potential. Devices designed on PI technology can work at greater depth levels.

PI devices are great for finding gold treasures because they work well in mineralized ground and give accurate results.

Certain high-tech devices that use PI technology have a unique Gold mode that detects buried gold exclusively. A Canadian-made detector ranks highest in this regard.

Pulse induction uses a single coil to send and receive an electromagnetic field beneath the ground.

When the targeted metal objects are detected, the same coil receives the signals and sends them to the control box for further processing.

Pulse induction devices can’t find small gold, like nuggets or flakes because they have lower frequencies than VLF. Some high-frequency VLF detectors can easily detect gold nuggets.

Learn which one is suitable for you Pulse Induction vs VLF

GPR Systems or Radar Technology

GPR systems are not like ordinary metal-detecting devices. Metal detectors can find metals underground, but GPR systems can find things deeper.

These devices are costly and complex. They are used for geophysical research and in industries. They can also be used for professional mining and archaeology.

GPR systems have the capability of not only detecting metals but also detecting any underground anomaly.

When you use a survey, it tells you about the texture of the ground and finds things underground like gemstones, water, and cavities. This gives you a big picture of the ground.

Radar systems are used for treasure hunting and mining, but they are more complicated than VLF and PI technologies. You need to learn how to use them first.

They are highly advanced and need proper training to use them. In short, these are not metal detectors but expensive devices used for underground detections.

Comparison Chart for VLF Technology and PI Technology

VLF TechnologyPI Technology
Good for use in low-mineralized soilNot affected by soil mineralization. Can be used in both low as well as high-mineralized soil
Good discrimination features as they work on shallow depthsWeak discrimination power as the depth of buried item increases
Can’t work at more depthCan detect the target at great depth
Provides a wide range of prices depending on featuresMore expensive than VLF
Lightweight modelsHeavier models
Used for detecting single coins, gold nuggets, relics, or such other metals at shallow depthsUsed for treasure hunting especially gold, silver copper, or for metals present at greater depth 

Some Other Patent Technologies

These technologies are based on the above-mentioned technologies with little modifications in them. Many metal detection brands patent technologies based on VLF or PI technology. They also have further categories such as:

  • Broad Band Spectrum
  • Full Band Spectrum
  • Multi-Period Sensing (MPS)
  • Dual Voltage Technology (DVT)
  • Three Frequency Transmission, and many others based on VLF and PI technologies.


After reading this article, you should now be more knowledgeable about different metal detector technologies. Most detectors use VLF and PI technologies.

They provide good features for metal detection and are easy to learn and use compared to GPR or radar systems. They are suitable in terms of the price range, but with more advanced functions and greater depths, their price range also increases.

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