There are many types of metal detectors on the market, and now a brief introduction to make everyone have an understanding of this aspect.

Metal detectors are divided by function:

• Full metal detector. This type of detector can detect gold, silver, copper, aluminum, iron and other metals with different materials. This kind of detector has high detection sensitivity. This product is widely used for the presence of metallic substances in objects and underground.
• Iron metal detector. This type of detector is mainly used to detect whether there are ferrous metals (such as iron, cobalt, nickel and other magnetic metals) in the article, and does not detect other non-magnetic metals. It is a magnetic induction metal detector.
• Aluminum foil metal detector. This kind of detector is mainly used to detect aluminum film or aluminum foil packaging products, in the pharmaceutical and food industry, many drugs and food are packaged with aluminum foil and aluminum film, with this kind of equipment to detect.

Metal detectors are mainly divided by purpose:

One. Hand-held metal detector. This kind of detector is small and easy to carry, mainly used in public places security, check whether the goods and the human body carry metal objects.

2 Underground metal detectors. This kind of detector is widely used, in the military for mine detection, in archaeology to detect the existence of underground metal relics. It is also used to detect underground scrap metals, and there are also public security criminal investigations used to find metal weapons.

Three. Conveyor metal detector. This type of detector is used to detect body bags, boxes and other types of products on the production line, mainly to detect the presence of metal impurities in these packages. This type of product has a linkage function that automatically excludes suspicious items.

4 Drop metal detector. This type of detector is used to detect free-standing items, is used to detect granular and powdery products, mainly used in the plastic and rubber industries. As these items fall through the drop metal detector, upon detection of metal groceries, the system activates the separation mechanism to eliminate the suspicious item.

Five. Pipeline metal detector. This type of detector is mainly used to detect paste and sealed pipeline assembly line, detection of metal impurities in the pipeline, such as drugs, capsules and granular, powder items.

VI. Vacuum conveyor type metal detector. This type of metal detector is mainly used in vacuum production lines with high production and environmental requirements, mainly in the chemical industry.

Seven. Pressure Conveying Metal Detector. This kind of detector is mainly used for pressure transmission line, such as products with high pollution requirements, and the detection of liquid or viscous articles before packaging or canning. Generally used in the production of liquid food industry.

Eight. Flat plate metal detector. This type of detector is mainly used to check the products of the comparison book such as sheet and filamentous.

IX. Walk-through metal detector. The structure of this kind of detector is door frame type. When people walk or objects pass through the door type, such as people carrying or objects hiding metal objects, the instrument will alarm.

Metal detectors are divided according to the principle of structure:

• Electromagnetic induction type metal detector. This kind of detector is the transmitting circuit of the instrument to transmit an electromagnetic wave signal to the transmitting coil. When a metal target is detected, the original electromagnetic field will be affected, and the electromagnetic signal will change. The receiving circuit of the instrument amplifies and processes the weakly changed electromagnetic signal, and then the relevant circuit judges the detected metal attribute according to the conductivity of the metal, and then displays the detected metal target through sound or display.
• Pulse underground metal detector. The principle of this detector is that the main circuit part of the detector circuit is an oscillator in a critical state. When a metal object approaches the coil of the detector, the electromagnetic eddy current generated in the coil makes the oscillator in a critical state of oscillation stop working, so that the instrument alarms.
• Remote sensing underground metal detector. This type of detector uses all molecules that are in motion at all times and resonate when the wavelengths of a pair of matching quartz crystals intersect each other. Using the principle of geomagnetic field, when there is a metal target underground, it will affect the geomagnetic field. The instrument uses the two external antennas to point to cross and coincide to judge the detected metal. Due to the large error of this principle, this type of instrument has been eliminated abroad.