A metal detector is an electronic device designed to detect the presence of metallic objects in the ground, water or other media thanks to the properties of electromagnetic energy.
These devices are widely used in a variety of applications, such as archaeology, treasure hunting, security, mining, and the detection of metal objects in industrial products.
The metal detector consists of a main unit that contains the electronic components and a probe or coil that is used to emit and receive electromagnetic signals. When the detector is turned on, the coil emits an electromagnetic field and if there is a metallic object nearby, the field is affected and a detectable response is produced.
Metal detection is based on differences in the conductivity and magnetic permeability of materials. Metallic objects, such as coins, jewelry, or pieces of metal, tend to be more conductive and magnetic than non-metallic materials, such as soil or minerals.
This allows metal detectors to distinguish between the two and alert the user when a metal object is detected.
How Does a Metal Detector Work?
Although the details may vary depending on the model and type of metal detector, here is the basic operation:
The metal detector consists of a transmitter coil, which is an antenna that emits a low-frequency pulsating electromagnetic field. This coil is connected to an oscillator that generates the electrical current needed to create the magnetic field.
When the metal detector is activated, the transmitter coil generates a cone-shaped electromagnetic field that extends from the coil. The size and shape of the cone vary depending on the detector design.
If there is a metallic object near the metal detector, such as a coin or a piece of metal, the electromagnetic field induces electrical currents in the metallic object. These currents, known as Eddy currents, create their own magnetic field.
The metal detector also contains a receive coil, which is located near the transmit coil. The receive coil is designed to pick up changes in the electromagnetic field caused by nearby metal objects.
The induced currents in the receiving coil generate a weak electrical signal that is amplified by the metal detector. This amplified signal is processed and analyzed by a detection circuit.
The detection circuitry compares the received signal with predefined patterns and settings configured by the user. These patterns and settings help distinguish between different types of metals and filter out interference caused by unwanted objects such as soil or minerals.
If the metal detector identifies the presence of a metallic object according to the established parameters, it emits an alert signal to the user. This can be in the form of an audible sound, a vibration, or a display on the detector's screen.
What Is a Metal Detector Used For?
Metal detectors are used in a wide range of applications in various industries and contexts. Some of the most common uses are:
Security: Metal detectors are widely used in public places, such as airports, train stations, stadiums, schools, and government buildings, to detect metal weapons and prevent dangerous objects from entering.
Mining and prospecting: In the mining industry, metal detectors are used to locate and extract valuable minerals and metal deposits. They are also used in prospecting for gold and other precious metals.
Archeology and Treasure Hunting: Metal detectors are essential tools in archeology and treasure hunting. They help locate and recover valuable and historical artifacts buried underground, such as ancient coins, jewelry, and relics.
Food industry: In the food industry, metal detectors are used to ensure the safety of products. They are used in the production line to detect undesirable metal contaminants in food, such as metal chips, wire fragments or metal particles.
Lost Item Recovery: Metal detectors are used by hobbyists and treasure hunters to find lost items such as jewelry, keys, coins, and other items of personal value.
Construction: In construction, metal detectors are used to locate pipes and metal cables hidden in walls and floors before drilling or excavation work to prevent damage to underground infrastructure.
Industrial quality control: In industrial production, metal detectors are used to inspect and verify the presence of metal components in products, thus ensuring quality and compliance with manufacturing standards.
Metal Detector Prices
Metal detector prices can vary considerably depending on the detector type, brand, features, and quality. Here is a general idea of the price ranges:
Basic Metal Detectors: The simplest and cheapest models can be priced from approximately $50 to $200. These detectors are usually low-end and offer basic metal detecting features.
Mid-Range Metal Detectors: Mid-range metal detectors typically range in price from $200 to $700. These models offer additional features and adjustments such as metal discrimination, increased sensitivity, specialized search modes, and greater depth of detection.
High-End Metal Detectors: High-end metal detectors, used by serious hobbyists, professionals, and in specialty applications, can be priced from $700 and up, even going as high as several thousand dollars. These detectors offer advanced performance, increased sensitivity, precise metal discrimination, customizable settings, and additional features such as advanced displays, GPS, multi-frequency technology, and more.
It is important to note that these prices are only a general guide and may vary depending on various factors. Also, it is possible to find used metal detectors at lower prices.