CHAPTER ONE
INTRODUCTION
1.1    Preamble
Durability is the assurance or probability that an equipment, machine or material will have a relative long continuous useful life, without requiring an inordinate degree of maintenance. It is the ability to undergo permanent deformation without cracking or fracturing.  
Durability testing is performance testing equipment used to determine the characteristics of a system under various load condition over time. This testing help us to identify the stability of a transaction response times over the duration of the test.
The importance of durability is to know the shell life of an equipment or agricultural material like the other dimension of quality, it is easier to plan durability into a product design and manufacture process that it is alter the finished product. There are many ways to increase a product durability, you can increase it’s by using durable part an modules in your product. Another way to increase durability is to use redundancy redundant part can vastly increase durability, however it will increase the product weight and cost as well. And finally another way to increase durability is to design a product or equipment for the most demanding user, that way to the average user the products appear to be very durable (Tomas foster 2001).
      When designing a product and its durability, you should design with your product base, user base, manufacturing base and value base in mind. Difference product bases require different levels of durability. The difference can be seen in an equipment, vehincles e.g (the two types of ford vehicles, the crown Victoria which is a law enforcement vehicle and the focus which is an economic car both vehicles are design from the ground up to be different types of cars with the different levels of durability.  Another example is a non durable product is the common light bulb. Light bulbs are design to last about a year or less and the slightest power surge or vibration can break their filament , rendering them useless. It would be nearly impossible to increase the durability of finished light bulb. However if you design light bulb for extended life and use a quality manufacturing process, you can drastically increase the durability of the light bulb (Hall, 2001).
1.2   Statement of The Problem
Agricultural material during processing of briquette or pellet is one of the most environment problems in developing countries. The unavailability of equipment to test the durability of briquette/pellets produce from biomass cannot be over emphasized, hence there is need to develop a machine to solve these challenges.
     However the decreasing life span of  agricultural material draw the attention to the need to consider an equipment which will determine the span of a material.
1.3    Durability Characteristics
Durability characteristics are stated below:
i.    Dust resistance.
ii.    It will free from fire resistance.
iii.    Radiation hardening.
iv.    Thermal resistance.
v.    Rot proofing.
vi.    Rust proofing.
vii.    Toughness.
viii.    Water proofing.
ix.    Ability to withstand wear, pressure or damage.