Chapter 34, Problem 34.15QAP

Interpretation Introduction

(a)

Interpretation:

The name of a laser diffraction instrument, its operation and uses is to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique. Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles. soil and its steadiness when wet.

Answer to Problem 34.15QAP

The instrument Partica LA-950 Laser Diffraction Particle size Distribution Analyzer. is built up by Horiba. Have very close tolerances. It is quite automatic in terms of functioning. The accuracy of the instrument is $+/-0.6\%$.

Explanation of Solution

There is a instrument in the market developed by the company Horiba named as Partica LA-950 Laser Diffraction Particle size Distribution Analyzer.

The material for which test has to be performed, placed in the sample cell. The two laser beams, depending upon the size of the test sample are scattered at an angle. This angle is proportional to the particle size. The scattered light is detected by the photodiode.

The software which controls the instrument correlates the scattered light with particle size.

The instrument is consisting of $650\text{nm}$ laser diode and the other is $405\text{nm}$ light emitting diode. The detection system is made up of silicon photodiode. The accuracy is $+/-0.6\%$ of tolerance. The precision of the instrument is $+/-0.1\%$.

Interpretation Introduction

(b)

Interpretation:

The range of particle size which instrument can measure is to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique. Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles. soil and its steadiness when wet.

Answer to Problem 34.15QAP

The instrument can measure particle size from $0.01$ to $3000\text{microns}$.

Explanation of Solution

The instrument has wide range of measurement of particle size. The range of the instrument is $0.01$ to $3000\text{microns}$. It suggests that the size of very small particles can also be measured.

Interpretation Introduction

(c)

Interpretation:

The sampling accessories of Partica LA-950 Laser Diffraction Particle size Distribution Analyzeris to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique.Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles. soil and its steadiness when wet.

Answer to Problem 34.15QAP

The instrument has powder jet dry feeder, miniflow and slurry sampler as the accessories.

Explanation of Solution

The sampling accessories are used for preparation of sample. They had pre-defined dimensions of sample like particle size etc. In the Partica LA-950 Laser Diffraction Particle size Distribution Analyzer there are following sampling accessories are available.

1. Powder jet dry feeder
2. Miniflow
3. Slurry sampler

Interpretation Introduction

(d)

Interpretation:

The size of the Partica LA-950 Laser Diffraction Particle size Distribution Analyzer is to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique.Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles. soil and its steadiness when wet.

Answer to Problem 34.15QAP

The dimensions of Partica LA-950 Laser Diffraction Particle size Distribution Analyzer is $332\text{mm}\times \text{321}\text{mm}\times \text{244}\text{mm}$ and the mass of the instrument is $56\text{kg}$.

Explanation of Solution

The size of the instrument is small comparatively.The dimensions of Partica LA-950 Laser Diffraction Particle size Distribution Analyzer is $332\text{mm}\times \text{321}\text{mm}\times \text{244}\text{mm}$ and the mass of the instrument is $56\text{kg}$.

Interpretation Introduction

(e)

Interpretation:

The model used by the software for measurement of particle size is to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique.Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles. soil and its steadiness when wet.

Answer to Problem 34.15QAP

The models followed for analysis of particle size are as mentioned below.

1. Mie scattering theory
2. Fraunhofer diffraction theory

Explanation of Solution

The software helps to correlate the particle size with the scattering angle. There are numerous models available for analysis of particle size. The Partica LA-950 Laser Diffraction Particle size Distribution Analyzer uses the following two models based on the following theories.

1. Mie scattering theory
2. Fraunhofer diffraction theory

Interpretation Introduction

(f)

Interpretation:

The method of automation of particle size analysis is to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique.Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles soil and its steadiness when wet.

Answer to Problem 34.15QAP

The method of automation of particle size analysis is fully automated.

Explanation of Solution

The automated analysis makes the particle size measurement more accurate. The Partica LA-950 Laser Diffraction Particle size Distribution Analyzer has auto sampler and built in automation. The slurry sampler is also there which is equipped with a robotic arm sampling system. Therefore in this instrument the analysis of particle size is fully automated.

Interpretation Introduction

(g)

Interpretation:

The research paper in which technique of laser diffraction is used for determination of particle size is to be stated.

Concept introduction:

The size of particle is measured by laser diffraction technique.Laser diffraction investigation is utilized here to contrast molecule size dispersions with the help in this case just as discover cycles of progress in estuaries that happen due to various particles soil and its steadiness when wet.

Answer to Problem 34.15QAP

In the paper G.Eshel, et al “2 Critical Evaluation of the use of Laser Diffraction for Particle size distribution Analysis” Soil Sci.Soc. Am. J. $68:736-743(2004)$ the method of laser diffraction has been utilized.

Explanation of Solution

The reference of the paper in the literature is given below

G.Eshel, et al “2 Critical Evaluation of the use of Laser Diffraction for Particle size distribution Analysis” Soil Sci.Soc. Am. J. $68:736-743(2004)$.

In this work the relation between the particle size distribution obtained by the combined sieve-pipette method and similar obtained with laser diffraction method was studied. They used Beckam-Coutler LS-230. $750\text{nm}$ laser beam was used. This instrument has range of $0.04$ to $2000\text{micron}$. The analysis model was Mie scattering theory.

Two different particle sizes were analysed. One set has shown good correlation and another set has shown poor correlation.