Different Types of Metal Detectors

Different Types of Metal DetectorsMetal detectors have been in existence for many years. In their former years, they were developed as a way to detect explosives. However, the first metal detector was invented by Alexander Graham bell in1881. Since then, the concept of how they work has remained largely unchanged. They work on the two concepts of electricity and magnetism. Refinement of this technology over the years has led to the development of the different types of metal detectors currently in existence.

Beat Frequency Oscillation

This is among the most basic of metal detectors. The concept behind how it works is very easy to understand. This metal detector is considered weak and is the option most commonly used in most electronics shops. It has the ability to find objects located about two feet below ground. All metal detectors use a coiled of copper rolled around a ring of iron or steel. The metal detectors have one large ring that is attached to the base of the detector. In addition, it has another tiny ring attached slightly higher. The coils are both connected to oscillators that can generate a frequency.

However, both of these coils operate at a different frequency. This difference is what the speakers attached to the metal detector detect. This speaker(s) usually comes in the form of a wearable headpiece. They produce an audible steady hum that can be heard by the person using the detector. When the base coil comes across a metallic object, the interaction of electromagnetics causes an interference in frequency transmission. This interference is what is used as proof of the existence of a metal object.

Very Low-Frequency Detectors

This is one of the most popular metal detectors currently in use. This is especially so among experienced treasure seekers. The detector can be highly accurate and sensitive. This coil also has a pair of coils, which work together. The first coil is the transmitter, usually giving off an intense electric current. The second coil is a receiver; it picks the signal from the main coil and amplifies it many times over.

The transmitter coil works by looping a magnetic field above and below ground. This field usually extends about two feet into the ground. The field usually stays that way until it comes across a metal object. When this happens, the object develops a magnetic current. This current then interferes with the perfect magnetic loop running into the ground. Thus, the secondary coil picks up the interference. This coil magnifies and sends into an audio system attached to the metal detector. Thus, the person is able to tell if there is an object in the ground. The beauty about this detector is that each metal objector generates a different frequency.

Highly magnetic objects such as steel or iron generate a very power field. This field is quite distinct and some detectors have the technology to indicate this. As a result, one does not waste endless hours digging up worthless objects. In addition, it can detect objects with a very low magnetic pulse. This includes precious objects such as gold. Ultimately, this is the aim of buying a metal detector. As a result, it would be self-defeating not to invest in such a good metal detector. With this type of metal detector, one has a higher chance of discovering precious stuff buried underground.

Pulse Induction

Different Types of Metal DetectorsThis is one of the latest innovations in detecting metallic objects. Guards commonly use this type of pinpoint detectors for detecting concealed weapons at security checkpoints. However, the technology is not very efficient in differentiating the different types of metals.

This technology relies on the simple theory of echolocation. For instance, if someone were to make a sound in a padded room, most of the sound would be lost. If they to repeat the same in a room full of hard surfaces, they would experience a very powerful echo. This is how pulse induction works. The detector usually relies on one coil or a number of coils that work as one. This is unlike other detectors that relies on two complementary coils working together. Furthermore, the detector works by sending a short burst of powerful current through the coil(s).

This pulse then disappears and the magnetic field quickly reverses. This then generates a short electric current, which then disappears. The current generate is used to generate a report on the objects present in the ground. If there is a magnetic object buried in the ground, it will undoubtedly interfere with the current generated. This model works well because the pulsing motion lets it detect only signals it has generated. The greatest impediment to using metal detectors is noise from the surrounding. Although it is more accurate at detecting objects, it is very hard to differentiate these objects. The detector remains one of the most expensive types of detectors currently in existence.

Industrial Metal Detectors

This is the most commonly used types of metal detectors for providing security. For obvious reasons, such detectors cannot be used for finding treasure. The most common industrial detector is the door frame detector. This detector is found in most airports and secure buildings. The detector on the basic principles of electromagnetism to work. This type of detector is very effective in deterring criminals from accessing a building with concealed weapons.

What to Look For In Metal Detectors?

For most hobbyists, they usually look for the price as their main consideration. However, this should not be the case. The price difference between an effective detector and a plaything is not very great. It can be a great way to turn a hobby into a serious craft if one has a good metal detector.


Traditionally, the local hobbyist shop used to be the place to find a good detector. Although this may still be so, it is advisable to do a bit of online shopping. These online stores have an unlimited capacity because they are so many. As a result, one is more likely to find better options online. In addition, most shops have an online presence. This means one can get top-rated detectors with features they may not be able to find at the local store.