Particle Analysis: Size & Shape Assessments of Powders
Understanding the advantages and disadvantages of individual techniques of particle analysis is a critical element in the analysis of particular powders’ particle sizes. It is important to understand the advantages and disadvantages when choosing between instruments and purchasing the most appropriate instrument for the goal.
In this article, we will outline some methods of particle analysis and present the benefits and drawbacks to each method.
Laser diffraction particle analysis method measures the particle size distribution by quantifying the angular variation in intensity of light scattered whilst a laser beam passes through a particulate sample that has been dispersed.
Laser diffraction is advantageous as a method of particle analysis as it is easy to operate, has a broad test range and has a high level of precision and repeatability. However, the instrument used for laser diffraction particle analysis is extremely expensive and the method’s results depends on the distribution pattern.
Air Permeability Fisher Method
Air permeability method is a particle analysis method which is non-destructive. A steady pressure pump is employed to pump out steady air which is then dried with a drying tube. The dry gas moves through the compacted sample area and then a pressure drop is created. The pressure drop is small is the powder has a large gap and large if the powder has a small gap.
In comparison to other particle analysis methods, the air permeability fisher method is low in cost, can test magnetic powders or hard alloys and has a simplified sample dispersion. The main disadvantage with this method is that it only quantifies the average particle size and not the distribution.
Sieve analysis is a method of particle analysis in which particles pass through sieves with a progressively smaller mesh size and weighing the material stopped by each sieve. This method is quick and easy with low instrument costs whilst also being reproducible and accurate. This method of particle analysis also results in a shortened analysis time.
Microscopic imaging is a simple method of particle analysis which is a direct test procedure allowing for shape analysis. However, the test cycle is long and it cannot test ultra-fine particles. Electron microscope particle analysis can measure particles at nanometer size however it comes at a higher cost.
Particle Analysis Automation from MIPAR