Experiment Part E: Microscopic analysis of particle size and shape

Title
Microscopic analysis of particle size and shape


Objective
To sketch the shape of the particle and state the overall shape of the particles of certain material

Date of Experiment

30th September 2014

Introduction

One of the common and easy ways to analyze the particle size and shape is through the direct observation on sand by using microscope. During the experiment, we were given different type of sand to be observed and analyzed such as the size, shape and arrangement.

Material and apparatus

Microscope, sand with particle size of 150 µm, 355 µm, 500 µm,850 µm

Procedure
1. 4 different types of samples were analyzed by using microscope, by observing the size and shape of given particle.

 

2. The particle shape is sketched and the overall particle shape of that material is stated.


Observation

Questions

1. Explain in brief the various statistical methods that can use to measure the diameter of a particle.

One of the method is projected area diameter which is measured based on the equivalent area to that of projected image of that particle. Another is the projected perimeter diameter which is based on the circle having the same perimeter as the particle. Both of these methods are independent upon particle orientation. They only take into account of 2 dimensions of the particle, thus inaccurate for unsymmetrical particle.

Feret’s and Martin’s diameter which take into account of both the orientation and the            shape of the particles is another method. They are two parameters in this method which      are Feret’s diameter and Martin’s diameter. Feret’s diameter is the mean distance         between two parallel tangents to the projected particle perimeter while Martin’s diameter is the mean chord length of the projected particle perimeter ,which can be considered as the boundary separating equal particle area.

2. State the best statistical method for each sample that you used.

The best statiscal method is Feret’s and Martin’s diameter because it takes into account the three orientation by using two different diameter. This will give an average value of diameter in more orientation and giving an average diameter value which is more accurate.

Discussion

The ability to accurately analyze and characterize particle size and shape by image analysis can significantly improve the manufacturing efficiency. It can also improve product performance for maximum effectiveness. So we use of microscopy and image analysis as the most reliable technique to characterize particle shape and characterize a particle size and volume distribution.

During the experiment, we put different types of sand on slide to be directly observed them using a light microscope. The sand should be spread evenly and just thin layer to avoid agglomeration that will affect the observation. We observed that the particles are irregular in shape. The size analysis is carried out on two-dimensional image of particles which are generally assumed to be randomly oriented in 3-dimensional and they are viewed in their most stable orientation.

Conclusion

Different types of sands have different shape and size which can be analyzed through a light microscope. 

Referrences
1. http://cma.tcd.ie/misc/particle_size.pdf
2. http://www.nature.com/nature/journal/v162/n4113/abs/162329b0.html