New era of human security consciousness of underground metal detector
The world's first underground metal detector was born in 1960. At the beginning of the industrial era, the underground metal detector is mainly used in industry and mining. It is a powerful helper to check the purity and benefit of minerals. With the development of society, crime cases are on the rise. In 1970, the underground metal detector was introduced into a new application field - safety inspection, which is the rudiment of the metal detection door we use today. Its appearance means that human cognition of safety has entered a new era.
The underground metal detector is made of advanced technology. It has the characteristics of wide detection, strong resolution and easy operation. Metal detector is mainly used to detect and identify buried metal objects, so how does it work?
There are usually two copper windings inside the coil. When the current flows from the battery to one of the windings, the generated electromagnetic field is directed to the ground, so this winding is usually called the emission winding. Metal objects have conductivity and can make electromagnetic field change. The change of electromagnetic field caused by the appearance of metal objects is picked up by the second winding in the coil, so this winding is called receiving winding.
The change of electromagnetic field caused by metal is sent to the control box, which sends an audio signal to remind the operator. Metal detector can distinguish many kinds of metals, which is realized by testing the conductivity of metals. The system can delete unnecessary response signals, ignore metals like steel, iron, can lid or bottle lid, but send signals to metals like gold, brass, silver, etc.
The emergence of a product has led to the development of an industry, so the security inspection industry, which is both unfamiliar and familiar, began to enter the market. Over the past 40 years, the metal detector has experienced several generations of changes in detection technology. From the initial signal simulation technology to the continuous wave technology to the digital pulse technology used today, the simple magnetic field cutting principle of the metal detector has been introduced into a variety of scientific and technological achievements. No matter in sensitivity, resolution, detection or performance, there has been a qualitative leap. With the improvement of product quality, the application field has extended to many industries.