A Complete List and Concepts of what do Metal Detectors Detect

An ideal metal detector can detect the metals that have a good conductivity of electricity. The circuit of a metal detector identifies the metallic objects through electric conductivity. Therefore, the metals have the greater electric conductivity are easily detectable by the metal detectors. Now, we will come to know about the conductivity of electricity and what do metal detectors detect metallic objects in the line. Because the electric conductivity defines the aspect of metals during a detecting process.

Metals that Detect a Metal Detector

From the above discussion of what do metal detectors detect, we assume that the metals with high electric conductivity are detectable by the metal detectors. So, the following metals are considered as highly electric conductivity and easy to detect by the metal detectors. Gold, silver, iron, copper, brass aluminum tin lead bronze. On the other hand, the metals that are not highly conductivity of electricity considered as non-metal or non-detectable object. Gemstones, bone, diamond, pearls and paper are non-detectable objects by metal detectors. Because they have zero scale of electric conductivity. So, they are very difficult to detect as metal. Moreover, the metal detectors do no find them easily.

What is Electric Conductivity?

Conductivity is a measurement of electric charge or heat that passes through a metallic object. In addition, a conductor is a type of material that has a very poor resistance to the flow of the electricity. However, materials are categorized as metals, insulators and semiconductors. Therefore, the metals such as silver, gold, copper, aluminum, brass etc. are more conductive and the insulators such as plastics, wood, ceramic etc. are the least conductive. The electric conductivity, however, defines of how well the electricity passes through a metallic object. There are many evidences that the copper is a thing that has an optimum measure of electric conductivity.

Metals that have the Least Electric Conductivity to the Most Electric Conductivity

According to material science, there are three basic types of metals. They are ferrous or magnetic metal, Non- ferrous or non-magnetic metal and stainless steel. However, the short definition of the three types of metals is given below.

1. Ferrous metal: The ferrous metal is a type of metal that can attract to a magnet easily. Iron and steel are that type of metal. Because they easily catch the magnet when to face-to-face. The ferrous type of metal is easily detectable by a metal detector. In fact, these types of metals have a rapid use in industrial activities. Pins, screws, paperclips, staples, thumbtacks, nails, welding and washers have good conductivity of electricity. So, they are easily detectable by a metal detector.

2. Non-ferrous metal: Non-ferrous metals generally do not attract to a magnet. But it has less electric conductivity. Due to have less electric conductivity, it sometime is very difficult to detect as ferrous metal. Because the electric flows is very thin within thin type of metals. Manganese is an example of non-ferrous metal. It’s hard to find out as a metal object.

3. Stainless Steel: Stainless steel is also a metal that is very difficult to detect by any metal detector. Because its electric conductivity is too poor to detect it as ferrous metal. Furthermore, due to have its slight magnetic permeability, it is very hard to identify as metal. The metallic sphere of the stainless steel must be 50% higher than a ferrous sphere to get the equal signal during a detecting work.

The Comparison Chart of the Metals Related to Conductivity of Electricity



Conductivity %


Pure Silver






Pure Gold















Pure Iron






Phosphor Bronze



Stainless steel



Pure Lead





How a Metal Detector Detect Metals Using Electric Conductivity

There are different types of metal detectors work in different ways. The science of a metal detector is that a metal detector contains a coil of wires that is wrapped around the head of the handle. It is called transmitter coil of the metal detector. When a metal detector is run then the electricity flows through the metal detector’s coil of wires and instantly a magnetic field is developed around a certain area of searching operation. When you will sweep the metal detector back and forth, it means you are making the magnetic field moving around it.

In fact, if you move your metal detector over a metallic object and the moving magnetic field incorporates with the atom inside the metal detected by the metal detector. We can alternatively say that, in this process the metal detector makes some activities in the metal. Otherwise, if we apply the electricity in a piece of metal object, it will create the magnetism as well.

So, in a metal detecting operation, if you move your metal detector exactly over a metal object, then a second magnetic field will appear from detector to the metal. Moreover, the second coil of the metal detector known as receiver coil will pick up the information about the aspect of the metal detected. Then the display unit of the metal detector will show all the information the detecting object. The loudspeaker also helps sounding about the detected metal.

Turning to the end

This is interestingly may happen to grow curiosity about a metal detector and the detectable objects before buying a metal detector. So, any way, we are almost clear about the facts now. In fact, we have cleared whole about the metallic objects and the science of metal. As a result one can not only identify the detectable objects but also will narrate of being the metals detectable or not. Because the reasons behind a metal to be detectable is an electric conductivity. The theory is all in all here. If a metal object has a good response of electric conductivity, then we can easily do our metal detectors detect the objects. So, the contacts of electric conductivity through a metal defines the nature of the metal object. It’s informative.

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