What Is No Motion Pinpoint on a Metal Detector?

No motion pinpoint on a metal detector is a feature that allows the user to find or "pinpoint" an object that is buried without moving the detector. Metal detectors are made up of three to four parts: the search coil, the shaft, the control box, and as an optional feature, the stabilizer. The pinpoint sensor is in the search coil. Metal detectors that have no motion pinpoint as a feature are not the basic models.

Identification

The search coil, also known as the search head, loop, or antenna, is located at the bottom of the metal detector. It is typically shaped like a disc and has, no openings, one opening, or multiple openings. The shaft connects the search coil to the handle of the metal detector. Some models have a wire that connects the search coil to the control box wrapped around the shaft. On other models, the wire is inside the shaft. The control box is the brain of the entire system. It contains the circuitry, the speaker, the batteries, and the microprocessor. Some models have an audio output to plug a headphones jack into. The optional stabilizer is like an arm brace. When it is attached, the user's forearm fits inside to maintain a steady sweep from side to side.

Function

Turn the metal detector on by pressing the "Power" button. The metal detector has a button or switch near the handle to control the no motion pinpoint feature. Press the "Pinpoint" button or toggle the switch labeled "Pinpoint" to activate this feature. The user then simply holds the metal detector in front of their body as they walk. When the metal detector pinpoints a metal object, it produces an audible sound. On some models, the control box can be set to look for certain metals and will display the type of metal found and how deep it is.

Use

Man using a metal detector

Metal detectors work by using a magnetic field. When the metal detector is turned on, the magnetic field penetrates the ground. As the magnetic field penetrates the ground, it is looking for a metal to interact with. If the control box is set for an exact metal, it will only look for that type of metal. Once the magnetic field finds a metal, it creates an opposite magnetic field in the metal. The magnetic field from the metal bounces back up to the coil and the metal detector creates the audible sound.

Considerations

When the pinpoint feature is activated, the metal detector becomes an all-metal detector. This means that it looks for and detect all types of metal and not just what is specified. The magnetic field is strongest in the middle of the coil, so the pinpoint feature has a harder time picking up metals closer to the edge of the search coil. In this case, swinging the metal detector helps to pick up items on the fringe.

References

• East Texas Metal Detectors: Pinpointing With Your Detector
• University of Alaska: How Metal Detectors Work