Some of the physical properties of agricultural produce include the following:

1. Shape indices
2. Moisture content

The moisture content is discussed HERE . Now we shall focus on the shape indices of Agricultural materials.

Determination of Some Shape Indices of Agricultural Materials

Introduction

     One of the physical properties of Agricultural material is what is called the shape index. Shape index is how the material in question looks like in physical, talking about the shape, the length, breadth and height of the material. Moreover, for the sake of this practical we shall try to explain in depth the terms used to describe the shape index of biological materials:

Some Useful Terms

1. Major diameter: The major diameter is the length of the material in question i.e. it is the longest side of the materials in question. It is denoted by 'a'
2. Minor diameter: This is what we normally call the width of the any shape or material but in biological terms it is called the minor diameter. It is denoted by 'b'
3. Intermediate diameter: The intermediate diameter is the height of the biological material and it is denoted by 'c'

Some other physical properties relating to shape index are the following:

1. Geometric mean diameter
2. Sphericity

Reasons for the determination of these properties

     The major purpose of determining all these parameters as an agriculturist or an Agricultural engineer is to have the understanding of the materials we are trying to handle by a machine or trying to design a machine to handle it. Let take for instance, as an agricultural engineer we want to design a maize Sheller, we need the knowledge of the shape i.e. is it oblong, circular, square, ellipsoid? We need to know the length, width and height of the maize. All these parameters will help in the design of the Sheller.
     Also we used these parameters in design of machine part like screen of a maize, rice and beans processing machines.

Objective(s) of the Experiment

     This experiment is to help to determine the shape indeces of agricultural materials

Equipments and Materials Needed

All we need are our measuring instruments like:

1. Vernier caliper
2. Micrometer screw gauge
3. Ruler
4. You should probably use a digital instrument to make the work faster and easier because determining the shape index of biological materials requires a lot of replicates.

Procedures

The procedure is simple; take each material and use your Vernier caliper or micrometer screw gauge to determine the major, minor and intermediate diameter of the materials. You have to do about 50-1000 replicates for standard results.

Results and Calculations

      Record the:

• Major diameter as a
• Minor diameter as b
• Intermediate diameter as c

Now:

Credits: Wasiu Mayowa Tiamiyu. Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.