Description
INTRODUCTION
- Background to the Study
In the 18th century there was a great demand for metals by factories. It was at this time that the industrial revolution began. The increasing magnitude of the demand led scientists and engineers to invent a machine that would save effort and cost and reduce the time wasted in finding metals. Success was registered in 1830 as a metal detector was produced (Divya, 2015).
From that moment on, the vast application of the device has brought about different types of metal detectors (Mohammed, 2011).
One area of application of metal detector is security. Nowadays, the metal detector is used to identify metallic devices such as bombs, guns for security purpose. To avoid any illegal or unauthorized entry of metallic objects, bombs, knives, guns within the luggage bags of the person carrying them in public places like theatres, shopping malls, parks, airports, hotels, railway stations. A security system is developed by using proximity sensor which is named as a metal detector. So, a metal detector is used in many robotic or electronics projects to detect any present metals which are nearby or the existence of hidden items within objects.
Miners will find this project useful as it provides an easy and an energy saving method for mining metals such as gold.
The military will benefit immensely from this project as it will help in detection of bombs.
Metal detectors work on the principle of generating an oscillating magnetic field which according to Eddy Current phenomenon is capable of inducing current in metals. The circuit for creating an oscillating field is made up of an inductor and a capacitor basically (Electronics Hub, 2017). Some principles such as proposed by Colpitts, Hatley and Clad can be used to generate oscillating fields too.
In addition to creating oscillating magnetic field, metal detectors have a system that keeps track of the reference oscillation so that when the oscillation frequency changes as a result of the presence of a metal this change can be manipulated to sound an alarm to the user. For this reason metal detectors have two oscillating fields called the search coil field and the reference coil field. The search coil produces the oscillating field while the reference field is tuned to the oscillating frequency of the search field (Chirag, 2016). When a metallic target enters the search coil field there will be a change in the oscillating signal frequency of the search field. The change is electronically manipulated to give a sound and turn on an LED.
The improved part of a metal detector involves controlling a metal detector remotely from a distance of 20 metres. This requirement divides the design into transmitter and receiver sections. The transmitter section is a portable remote control whose function is to switch ON and OFF the metal detector. The receiver section is fixed to a mechanical support.
When a metal is in the vicinity of the field created by the search coil, an LED is switched ON and the buzzer sounds the alarm automatically.
1.2 Statement of the Problem
Going by the sophisticated means armed robbers adopt these days in breaking into banks, super markets and highly secured areas or the activities of assassins in conference hall, airport, hospital e.g. there are every indication that they are out for the worst and a better way of lessening the harshness of these menace is to get highly alerted security wise. No security system will be optimized or complete without the installation of metal detector. This will stop or reduce barest minimum, the cases of men of the underworld breaking into banks, hotels, conference hall, homes, hospital e.t.c systematically undetected.
An improved part of this device involves detecting an object from a certain distance and controlling the ON and OFF the metal detectors using RF technology over a range of 20 metres which overcomes the limitation of the existed metal detectors.
AIM AND OBJECTIVES OF THE STUDY
The aim of this work is to build an improved handheld arduino based metal detector which uses LED and Buzzer as the output device, that detect an object from a distance 20 centimeter and controls the ON and OFF the metal detectors using RF technology over a range of 20 metres. The objectives of the work are:
- To build the system prototype
- To remotely switch ON and OFF the metal detectors using RF over a range of 20 metres
- To address issues of security especially the use of guns and other metallic objects
- To solve societal problems relating to security and create an enabling environment free from the use of guns, bombs and other harmful metallic objects
SIGNIFICANCE OF THE PROJECT
The significant of this project is to construct a functional electronic detector security system, which will be beneficial technology to human beings. This project will also bring technology nearer home especially to the student, and to me as the designer, and the contribution in the advancement of technology, thus helping them to assemble, design and construct projects based on simple component and material locally or foreign.
Again, this project will encourage indigenous technology and discourage the large expense being made on foreign security systems. All these were born in mind during the assembling, designing construction and casing of this project.
With the help of a hand held detector, security personnel can physically detect if a person is carrying a metallic object. On the other hand, walk through metal detectors are much quicker, and they alert the security personnel of dangerous objects such as knives or weapons.
Metal detectors are able to deter potential would-be criminals because the would-be criminal will think twice before walking through a security check point.
