What Is a Metal Detector?
Metal detectors are devices designed to detect metal particles in liquids or solids. Metal detectors are commonly employed as security measures in airports, prisons, schools, courthouses and military facilities; portable models may also be seen at concerts and sporting events. Most detectors contain sensors which monitor electrical conductivity, magnetic permeability and size of potential contaminants that they detect; these may include ferrous and nonferrous metals with various levels of sensitivity depending on metal detectors for beginners their material being examined.
Single and balanced-coil systems are two primary forms of metal detectors, respectively. Single-coil devices rely on eddy currents created as metal passes through an inducing coil's magnetic field to alter its apparent impedance, creating secondary magnetic fields which alter its apparent impedance, creating signal changes which sensors can pick up on. On the other hand, balanced-coil detectors employ two identical detector coils which work in tandem; when an object such as metal passes through one coil it disrupts its high frequency magnetic field resulting in an imbalance that causes its voltage produced from two coils which then causes impedance change resulting in altering impedance changes which alters both devices' apparent impedance causing signal changes which sensors pick up on that change causing alarm signals from sensors on nearby sensors.
Modern metal detectors feature sophisticated circuitry that enables the user to program various functions, such as sensitivity, discrimination, track speed and notch volume. Some even come equipped with built-in GPS technology so users can keep an account of where and what objects were found during searches.
Purchase of a metal detector can be a difficult decision that depends on its intended use. For instance, people searching beaches might prefer models equipped with waterproof search coils that work effectively in wet environments; other users may prefer models featuring multiple modes as well as frequency discrimination features for maximum versatility.
Some individuals enjoy discovering coins and small items while others have a deep-seated interest in history and want to uncover historical artifacts. Relic hunters require permission from private land owners as well as abiding by any applicable state or country regulations to dig for artifacts that could potentially earn significant sums of money when sold at auction.
Beat-frequency oscillator (BFO) metal detectors are among the easiest devices to use and include two coils of wire - one large in the search head and one small in the control box - connected to an oscillator that generates thousands of pulses per second and travel through them into radio waves which are picked up by a small receiver located within the control box. A computer analyzes this data before producing audible tones based on it; more advanced models contain multiple oscillators as well as advanced circuitry that enables more precise detection.