CHAPTER ONE 1.0 INTRODUCTION

Liquid has always been paramount to life on earth. The importance of liquid to life generally cannot be over emphasized. Generally without it life could have been so terrible. Considering the benefit and joy it has brought to life it needs to be monitored critically. The most dramatic thing about most liquid is that they need to process from it combined or impure form to a pure form before it can be used for its purposes. Because of it benefit and the long process involve in getting pure form of liquid a care needs to be taken as to avoid wastage of this pure liquid. Liquid is fundamental to all life on earth; while many people may still take its ease availability for granted, growing demands on the world s liquid resources highlight the importance of liquid to everyday life activity.

As many automobile devices e.g. cars, motorcycle, generator and many others cannot work without the aid of a certain liquid(fuel) this also shows the vast application of liquid even in an automobile industries all over the world. A very high percentage of world energy is harness from liquid (petroleum).

Nowadays everybody has overhead tanks at their homes. But everyone who has a water tank above knows the kind of problems they are facing.
Firstly there is no system to track the water level in the tank. Then there come a secondary problem that is when water is to be pumped and when pumping is to be stopped that prevent spilling of water out from the tank. Due to these challenges, there is wastage in energy and liquid.

Earlier on, there were several methods (traditional ways) for tracking the level of liquid in a tank. Like tapping down the side of the tank until changes in sound is heard or removing the cover and dipping in a measuring stick. The above stated methods are unreliable, inaccurate, and sometimes stressful and time consuming, especially when the tank is placed at a greater height or in an underground. Therefore the need for modern liquid level indicator arises so as to eradicate/reduces the above stated challenges.

The modern liquid level indicator is used to show the exact level of liquid in an overhead tank or a reservoir. It display percentage level of the liquid on the display unit i.e by showing 100% when the tank if filled up, 0% when there is no water and some calibrated percentages. At a certain level (critical level) the system begins to generate sound to draw human attention to this critical level so as not to run out of liquid unaware. The liquid level indicator operates on the principle of floatation. As long as the floater (sensor) floats on the surface of the liquid, increase or decrease in the level of the liquid causes the upward and the downward movement of the floater respectively.

The modern liquid level indicator saves time, energy, maintain liquid level, and prevent liquid overflow and same time sure that enough liquid is left in the tank.

1.1 AIMS AND OBJECTIVES

The design and construction of liquid level indicator is aimed at achieving the following goals.

1. To design and construct an electronic device that will conveniently indicate the level of any liquid in a tank or a reservoir
2. To regulate the usage of the liquid in various places to which its been used
3. To ease the difficulties encountered when trying to know the exact level of liquid in an overhead or underground
4. To know the precise and accurate level of the liquid in a container

1.2 SCOPE OF WORK.

The circuitory can be used to check the level of any liquid be it conductive or nonconductive as the design deals with the principle of floatation by changing the floater with the rest of the circuit remaining the same

1.3 METHODOLOGY AND SOURCE OF MATERIALS

The entire circuit diagram was first designed on proteus ISIS professional after which it was simulated and confirmed working perfectly. Each sub-unit of the circuit design on proteus ISIS professional software was transferred into breadboard with appropriate tests carried out. These sub-units design was now integrated to form the complete circuit of the system still on breadboard and was tested working which serves as a replica of how the work will ought to have been if it were to be on permanent (vero) board.

After confirming the workability of the system on breadboard it was now transferred into veroboard that was finally coupled with the constructed container whose content is to be measured

The entire electronics component used in the process of project design/construction was obtained locally from the market. Electronic books were also consulted as part of materials used which were referenced after the completion of the work

1.4 OVERVIEW OF THE DESIGN

The liquid level indicator consists of a power supply unit, sensing unit, control unit, and relay unit. The sensor (floater) moves up and down depending on the rise and fall in the level of the liquid. As the floater moves it varies the resistance of the variable resistance attached to the container. The variable signal from the resistor is now fed into the analoguedigital converter (ADC).

The ADC output digital signal is now sent to the micro-chip, the micro-controller now processes the signal being sent into it and it now instruct the 7-segment display to show the equivalent percentage level of the liquid.

As a result of this detection and control, the fuel level in the reservoir will be known and maintained as long as there is power supply.

1.5 SIGNIFICANCE OF THE PROJECT

The project focused on determination of liquid level in a fuel reservoir or fuel tank. It is believed that the findings in this project work will be of assistance to the following:

1. The control of water in overhead tanks by user.
2. The determination of petroleum product level in storage reservoir or tanks

1.6 PROJECT OUTLINE

Chapter one: This chapter gives a general introduction to the project. Aims and objectives, scope of work and significance of the project are also contained in this chapter.

Chapter two: This chapter covers the literature review that highlights previous work of the subject and also the level measure techniques which also show an in-depth look at various components and sub-circuits that make up the system.

Chapter three: This chapter contains the principle of operations and the detailed circuit design and the analysis of the project.

Chapter four: This chapter covers all the details of the construction and testing procedures employed to achieve the final product. It spans simulation of the circuit diagram on the computer, bread boarding and soldering of the components on the vero board, casing construction, test precautions taken, troubleshooting and result obtained, as well as the difficulties encountered, in the course of the construction and testing.

Chapter five: The chapter contains the conclusion drawn from the results of the testing, with reference to the objectives and goals of the project. The chapter also contains the recommendation for further work on the project topic in future.

CHAPTER TWO

2.0 LITERATURE REVIEW

2.1 HISTORICAL BACKGROUND

In order to obtain the level of liquid, various methods have been employed in the past time starting from the ancient eye level measurement where the liquid is placed in a transparent container and the eye is placed at the line of the best horizontality and at that point, the measure is taken as the level of the liquid. This is however prone to a lot of errors mostly arising from the observer. The need for a more reliable method of detecting the level of liquid in a tank or reservoir arises.