A metal detector is an electronic device employed to detect traces of metal, generally from the ground, a person, or cargo. Metal detectors can effectively penetrate through soil, wood and other non-metallic materials.
How does it work?
Metal detectors use the principal of electromagnetism. Typically, a metal detector comprises an electronic box, transmitter, a receiver antenna and a battery case. By battery power, the transmitter generates a magnetic field. If a metal item passes through the metal detector, it becomes magnetized due to the effect of the magnetic field. On receiving the electromagnetic signature, the receiver sends a signal to the electronic box. There is a speaker to amplify this signal. This produces a beep sound, indicating that there is metal contamination.
What are the different types of metal detectors?
Depending on specific situations, different types of metal detectors are available. For example, there are metal detectors exclusively for prospecting gold. Likewise, special metal detectors are available for relic hunting. Underwater metal detectors, coin detectors, and walk through metal detectors are other prominent types. Multi-purpose metal detectors are also popular nowadays.
What is product effect?
When passing through the metal detector, some food stuffs tend to generate a signal although no metal is present in them. This is known as product effect. It is mainly due to factors including acidity, fat content, moisture content, salinity and temperature.
What are the factors that affect the sensitivity of metal detectors?
Product effect, size and type of metal contaminants, and metal detector opening size are some of the factors that affect metal detector sensitivity.
What is the warm up time for metal detectors after the power is on?
For accurate detection of metals, metal detectors must be allowed to warm up for at least 30 minutes after the power is on.
Can burned and rustic metals be detected using metal detectors?
Yes. But, the detection sensitivity is based on the shape and orientation of the contaminants. In addition, it is difficult to detect minute particles.
Can metal detectors detect non-metallic contaminants?
Metal detectors cannot detect non-metallic contaminants.
What are the accessories required in metal detecting?
Among the accessories required for metal detecting are gloves, probe, knife, gator digger, and ground cloth.
What are the precautions to be taken when cleaning metal detectors?
To clean the main unit of metal detectors, hot water less than 40 degrees centigrade can be used. The dirt and particles present in the detector head must be cleaned frequently. It is also necessary to clean its conveyor belts. Neutral detergent and a plastic brush with soft bristles can be applied for the purpose.
