Chapter 1 overview of hand-held metal detector products

A hand-held metal detector is designed to detect metal  by people or objects. It can detect  carrying such as parcels, luggage, letters and fabrics carrying weapons, or small pieces of metal, The special appearance of its sensitive surface makes it easy to operate. Better than ring sensor. Ultra high sensitivity, special application in prison, chip factory, archaeological research, hospital etc. The hand-held metal detector (PD140V handheld metal detector, imported metal detector) is used to check the specific position of the person carrying metal.Can also cooperate with metal detection door to use, when "security gate" alarm discovers metal goods, use the handheld metal detector can find the accurate position that contains metal article. The metal detector USES rectangular detection head, detection area is 12 centimeters, inspect human body, complete inspection work from top to bottom.

Before using, first open the battery box on the back of the instrument and load the battery. This instrument USES the laminated battery of 9V. Please note that the nominal voltage on the battery must be 9V, and the other voltage must not be used. The power consumption of this instrument is very low, and each new battery can work for about 50 hours. When the energy of the battery drops to 10%, the instrument cannot work properly, and the speaker will make a staccato click, indicating that we must replace the new battery.

When using, security personnel with the hand holding the handle, the thumb press the start button, then loosen, instrument lights start flashing, trumpet at the same time a very slight hum, said instruments. The staff will scan the surface of the person (or object) with the device after it is turned on. If there is a metal object, the instrument will make a sound. After checking work, you should press the down button to avoid wasting battery power

How to determine the size of the metal

Physiology research shows that people's hearing is insensitive to the change of volume (logarithmic relationship), and is more sensitive to the change of tone (linear relationship), the instrument according to the above situation, with the tone of the discretion to determine the size of the metal objects, the advantage of this is different from other similar products, it can make us more correctly distinguish the different size of metal objects.

When the instrument probe scanning the body (object), if a relatively low noise, and the probe stays above the voice of the sound will gradually disappear, we can determine it is a small metal, such as belt buckle, zipper, etc. If the sound is very sharp, even if the probe stops and the sound continues, it must be a larger piece of metal, such as a dagger, a pistol, etc.

The second chapter   :the production technology of hand-held metal detector

Diversified exploration of new technologies

Multiple beam technique

Infrared detection is the most common detection technology in many detection technologies. In the active infrared detector, the development of single beam technology has been difficult to meet the requirements of the detector. According to HoneywellSecurity officials said, active infrared detector technology mainly USES the process a stop, belongs to the linear, already from the original single beam to beam, can effectively reduce false positives, so strengthening the reliability of the guard. In order to expand the scope for the prevention of overcome the common active infrared correlation range is insufficient to prevent defects, many manufacturers have developed many beam grating type active infrared correlation, it is actually an extension of the single beam active infrared technology

according to information ,the infrared beam detector process a stop, built a safe protection area, and once there is blocked by an object the infrared beam, the probe will reflect infrared signal interrupt to alarm, anti-theft function.

And single-beam infrared correlation only a set of rays, which makes the detector coverage only a small area, and thus become a flashpoint for thieves and criminals, therefore, have multiple sets of beam, can from different directions and angles were produced, the cross correlation of multiple beam technology. This technology makes the beam coverage increase and becomes more complicated, which greatly enhances the security of prevention and effectively reduces the occurrence of false and omission.

Shielding, spraying and pet detection technology

Detector at work often by some careless artificially vandalism or other object into the interference, misstatement or omission to happen, and, for a variety of avoid detection measures also has been studied, then several kinds of technology is the main barrier, the spraying and the technology of pet.

Because mobile detectors are usually based on passive infrared (PIR) techniques that detect the radiation heat of an intruder, they tend to be easily fooled by covering the detector, according to Bosch. The barrier system is in the detector lens are covered or blocked out an alarm, and today's anti block probe to further improve the advanced level, even if the transparent gel onto the lens will trigger the alarm. Therefore, a technique called "multi-point shielding and integrated spraying detection" can fully guarantee the probe's detection reliability. It includes the function of post-mirror photometric function, infrared receiver reflection function and integrated spraying detection, which can prevent the material flow through the front of the detector. Infrared receiver reflectance can prevent objects from approaching or blocking detectors. If a probe is installed in a vault, vault, etc., it will not be easy for the robbers to do so.

Cats, dogs, birds and other animals (including children) are often unaware of the false positives that occur in the detection area, and in order to avoid this situation, pet intrusion detection techniques are used