CHAPTER ONE

INTRODUCTION

1.1 Background Information

In the beginning metal detectors, couldn’t pick up everything deeper than one inch down. This time passes and inventors learn more, the capabilities of the detector have greatly improved, on July 2, 1881, America president, James Garfield was shot in the chest and the bullet was left behind. Alexander Graham Bell tried using one of the first original metal detectors, in order to help locate the bullet. Alexander Graham Bell was not able to locate the fatal bullet that was left behind. There was a revamped version of the one that Alexander Graham Bell used to help James Garfield with. Metal detectors have many uses, they are used medically to find metal in human body (Alexander Graham Bell 1881) Metal detectors are also use in the process of detecting land mines and prospectors also were very glad to use the invention. Constructions, is yet another field in which the metal detector is very welcome (Errata, 1994). In this case they use the metal detectors ability to search out steel reinforcement beams pipes and wires. Archaeologist, also use a metal detector to help in the findings of coin; and artifacts. Many people have become interested in the use of metal detectors, over the last few decades. A metal detector is an electronic instrument which detects the presence of metal nearby (Alexander Graham Bell, 1881). Metal detectors are useful for finding metal inclusion hidden within object s, buried underground. They often consist of an handheld unit with a sensor probe which can be swept over the ground for other objects. If the sensor comes near a piece of metal this is indicated by a changing tone in earphones, or a needle moving on an indicator. Usually the device gives some indication of distance; the closer the metal is, the higher the tone in the earphones or the higher the needle goes. Another common type of stationary “walk through” metal detector used for screening at access point in prison, courthouses, and airport to detect concealed metal weapon on a person’s body(Graves Metal, 1998). A magnetic metal detector is an electronic device that that uses magnetic sensor to find metal objects around, it is made of an oscillator that produces a.c that passes though coil which creates alternating magnetic field.

1.2     Problem Statement

We have experienced high rate of crime and corruption in recent years. This has call for more sensitive, efficient and dependable metallic detectors in some areas such as banks, seaports, airports, schools, shopping halls, prisons etc.

1.3   Aim and Objectives

To design and construct an handheld magnetic metal detector for the purpose of detecting, landmines, metal treasures, ore by miners etc.                                   

The objective of this project comprises the following:

•   To design and construct a more reliable, sensitive and dependable metal detector.

•   To improve on previous work done on metal detectors.

•   To design a metal detector suitable to checkmate the recent security challenges in NDA and country at large.

• Also use in the prison by prison warders and various checkpoints by the military and paramilitary  for search purpose                                                                

1.4 Justification

This project is significant in that it is being carried out at a period of unprecedented use of internet and other telecommunication networks in Nigeria especially in Nigerian Defence Academy

1.5 Motivation

This project was put up, due to various issues of urban menace, the present security instabilities and insurgency situation of our country (Nigeria), in areas like club centres, recreation areas, amusement parks, bank, hospitals, etc by some unlawful citizens, who are being aided and sponsored by some set of highly placed persons usually known as (godfathers).

1.5Significance of Study

This project is significant in that it is being carried out at a period of unprecedented uses of internet and other telecommunication networks in Nigeria especially in the military.

1.6 SCOPE OF THE PROJECT

This project and implementation report covers the design and the construction of a security metal detector (handheld) with indicator that will be ringing when metal is being detected.