Particle size and shape can greatly affect the performance characteristics of individual components of a mixture, as well as of the final product. The major drawback of standard microscopy for particle analysis is the time required, both for sample preparation, and for counting and measuring properties of the particles. Additionally, since this time is required for sample preparation and analysis, the microscope can only be used to observe one static sample at a time. While this is fine for basic research in an early discovery phase, it is unacceptable once it is necessary to look at a process in detail. First of all, the second phase of verifying a cause- and-effect relationship found in the discovery phase requires a statistically significant quantity of the particles to be analysed. This process is too time consuming for manual methods, and requires that some level of automation be brought to the measurements. Secondly, since this is an analysis of a process, sampling needs to be accomplished over a time period of the process. Indeed, many of these processes require continuous analysis over a period of time, an extreme example being the continuous monitoring of particles for purposes of quality control. While microscopy has many benefits for this, it has one important drawback: only a small amount of a given component can be examined at any one time.

As result, several technologies have been developed for automating the rapid measurement of large numbers of particles. One of the earliest technologies developed (and still very commonly used) involves rapidly determining a particle's size by measuring its electrical sensing potential. Most commonly known as the Coulter principle, in this type of system particles suspended in a weak electrolyte are passed through a narrow channel, which has an electric current flowing through it. The particles passing through this channel produce an impedance pulse that is directly proportional to the particle's volume. Assuming a spherical shape, one can quickly derive an Equivalent Spherical Diameter (ESD), which serves as a single number measurement to characterise the particle. These systems can process tens of thousands of particles per minute, which allows rapid characterisation of a sample's properties based upon a distribution of ESDs.

Other technologies that are used in particle analysis systems include light (or laser) obscuration and laser diffraction. All of these methods have the benefit of being able to very rapidly analyse large numbers of particles in a very short period of time. In a conventional microscope, it may take several minutes to count and size less than a hundred particles, while these systems can do the same counting and measuring of tens of thousands of particles in under a minute. From a statistical point of view, having measurements on huge numbers of particles in a sample increases the significance, confidence and repeatability of those measurements dramatically. Large amounts of data are quickly collected in a tabular form, with the results usually presented as a histogram of frequency versus particle diameter.

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