Notices For Design Of Probe Head Of Metal Detector

- Jul 04, 2019-

The simplest way to develop metal detectors is to directly select the finished metal detectors and develop their own mechanical conveying and other ancillary facilities. The advantages of this method are as follows: 1. Small investment. 2. Short development cycle. 3. High product maturity. Machinery enterprises usually choose this method when developing new products. AOTENG metal detector adheres to high-quality mechanical processing technology, providing you with high-quality testing machinery and metal separators and other equipment customized production, welcome to consult.


The design of conveyor and auxiliary mechanical and electrical facilities must be based on the characteristics of metal detection head. The main considerations are as follows:

1. No metal (conveyor belt, load-bearing bracket, bulk material baffle, etc.) can be found in any mechanical parts and parts passing through the metal testing head passage.

2. As long as the moving parts of the conveyor are made of non-magnetic materials such as SUS304 (axle of drum and bracket). The best choice of bearings is stainless steel or bearing steel, but demagnetization should be done when necessary.

3. If there are conductive loops around the metal detection head, they will be affected by the magnetic field of the gold detection head to produce eddy current. For example, the axis of the drum is metal (also considering brackets and other rotating parts), and the frame of the conveyor is metal, so that the axis of the frame and the drum constitutes a guide for the metal detection head. Electrically closed loop, in alternating magnetic field, alternating current will be generated in this loop. Since the drum moves relative to the frame, from the point of view of electricity, this movement produces the instantaneous characteristic of electrical connection, that is, the instantaneous disconnection or incomplete connection occurs on the electrical connection. At this time, the alternating magnetic field in the loop appears to be instantaneous. Time inequality is not conducive to the normal working state of metal detection head, which will inevitably lead to the failure of normal work.

4. Generally, the bigger the diameter of the channel of metal detection head is, the larger the influence range of magnetic field is, the larger the size of the conveyor should be accordingly.

5. If there are metal plates around the metal detection head, they will be affected by the magnetic field of the metal detection head to produce eddy current. If these metal plates do not move or shake, they will not have any effect, but as long as they move even slightly, they will produce changes in the external magnetic field, which will affect the normal work of the metal detection head. (Non-metallic materials are preferred for the flip plate of the exclusion device.

6. The subsidiary mechanical and electrical facilities, mainly small motors, solenoid valves, etc., mainly adopt the method of shifting position when working at low voltage, that is, changing the installation position and direction to reduce the adverse effects of its opening or closing moment. For high voltage components (220V AC small motor, etc.), zero voltage starting and zero current closure can be used.