Hand Held Metal DetectorMost people are familiar with the type of metal detectors used to find buried metal objects, as well as the type that are set up for people to walk through in stores, airports, and other areas. There is a third type of widely used metal detector, too: the handheld metal detector.These electronic instruments are usually used to detect metal on a person's body. In many cases, these handheld models are used when the walk-through type has been set off. You may see them in airports, as people are taken from the security line after setting off the detector's buzzer. There, they ensure that no guns, knives, weapons, or other metal objects are smuggled onto the plane by hiding them under the clothes and simply walking through the detector.Handheld metal detectors are available to suit many needs, although they are usually used in large establishments with many people walking through the freestanding metal detectors. They can be used in schools, courtrooms, corrections facilities, sporting events, and any other public area or event, and are especially popular for temporary situations in which installing a walk-through detector would be impractical.The main drawback of walk-through metal detectors is that they are unable to pinpoint the location of the metal object on a person's body. Handheld versions are often a must-use device for people with various medical devices containing metal; these people will set off a walk-through detector even when they are not carrying additional metal objects. By waving a handheld metal detector in front of the body, moving in a methodical motion from head to toes, the metal object can be precisely located. Often, it is used as a replacement for a strip search, which can be invasive and unnecessary. Although the public may feel a little inconvenienced by this search, most people understand the need, and of course it is much preferable when the alternative is a strip search.These devices consist of a control box, speaker, batteries, and microprocessor, connected to a shaft with a search coil. If the search coil moves over a metal object, it will set off the alarm. They work on the principle of pulse induction. A pulse is sent from the metal detector, and the response time is measured. A conductive metal will result in a longer pulse time than other materials, indicating the presence of a metal object.Handheld detectors such as these have other applications, too. For example, construction crews can use them to find nails or other metallic objects in trees, reclaimed building materials, or other locations. They may even be as accurate as an x-ray in finding metallic objects swallowed by children, depending on the sensitivity of the specific unit that has been chosen. Hand held detectors cause no radiation, unlike x-rays.Handheld metal detectors are often chosen as a direct replacement for other forms of searching. They require very little maintenance, and can be operated after just a brief training session. In addition, they are very accurate. Unlike freestanding detectors, handheld versions are portable. These multi-purpose detectors are a wise choice for many applications.