Now a day, there is now one how has not seen a Metal
detector, there are present in every place where ever there is a chance of
crowd, they are present in all those places. Either it may be Mall, Railway
Station, Temples, etc. Ever thought how they function. No Right, so this blog
is for ‘You’.
Firstly, there are different types of Metal detectors,
Hand-Held Device, Gate Keeping Devices, Ground searching devices.
History of Metal
detectors:
The Metal detectors were introduced/invented to search
antique items and gold under the ground and later used by military for
searching the hidden Land mines in war prone areas.
The size of the Machine Were Big and Bulky but Powerful and
Efficient in their job. Later on, they came into security purposes with light,
portable but less Powerful. (To compare, the bigger ones are able to detect
even a small knife and a small pin which is at 4, The bigger ones was able to
detect even a small knife and a small pin which is at 4 ft. below the ground.
But, the lighter ones can detect a small knife at distance of 1 ft. but not a
small pin.) So let’s see How they work
Functioning Principle of a
Metal Detector:
The main principle on
which the Metal detector works is Based on Maxwell’s equations. He is the one
who showed, the Omni present couples (Adarsha Dampatigalu) of the world- The electricity
and The Magnetism by his equations.
In this world, where ever you see Electricity you see
Magnetism and where ever you see Magnetism you see Electricity. This is the
principle behind Motors and Generators, where you have electricity you produced
magnetism and where you have magnetism you have electricity.
There are two coils present in scanning area (whatever type
of detectors it may be) transmitting coil and receiving coil. The Transmitter
coil has Circuitry which converts the given voltage to magnetic field and
conveys; The waves take elliptical path to receiver coil because of properties
of magnetism.
If any Metallic object interferes the field, the electrons
of the metal object changes there spins due to influence of the magnetic field radiated
by transmitter coil.
Due to spins, there is disorientation. Due to disorientation
there is electricity is generated. Since electricity is produced in metal, the
metal radiates its magnetic field. So extra magnetic field is produced and it
is received by the receiver coil.
There will be a Controller which measures the received magnetic
field and compares with the transmitted magnetic field. According to the compared
field the voltage is sent to the Buzzer Which Loudens or Softens the sound
based on the voltage given. Hence when the detector is close to the Metal
object or the metal object is big the sound of buzzer is loud.
This is how the Metal detector work. Hope You Have
Understood. Don’t forget to comment, +1, recommend and feel free to share. But don’t
copy.
And the scanner you see at the exit of shopping malls are
not Metal detectors they are RFID scanner, to know more about that Follow my
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