The introduction of microscopes in the 1600’s changed the world for scientists. For the first time, we could observe and record organisms too small to see with the naked eye. To this day, microscopy remains the most common instrument for sub-visible particle analysis, however there are many limitations.
Drawbacks of manual microscopy
The major drawback of standard microscopes for particle analysis is the time required to complete an analysis. Depending on the sample, it could take hours to prepare the sample, set up the slides, and measure any particles found.
Since you can only process one small sample at a time, it is difficult, if not impossible, to get a representative sample of the whole. Plus, when you’re only looking at a few particles, your results will not be statistically significant, therefore particle analysis results from microscopy may not be reliable or repeatable.
Finally, because microscopy is a manual process, human error can be introduced. Tired eyes, interruptions, and time of day can all have an effect on the operator, and therefore the results.
Imaging particle analysis offers a faster method
In an early discovery phase, a standard microscope might be just fine for particle analysis. However, when you’re ready to move ahead in your research and want to begin analyzing the size and shape of particles in large quantities, an imaging particle analyzer can provide the solution.
This was the case for Ross Clark, distinguished research fellow of global ingredient supplier CP Kelco, in San Diego. When observing the flow of powder particles in a customer’s powder educator, Clark suspected that shape variation of the particles from batch to batch was causing some variability in the flow – even though operators had already effectively adjusted airflow to resolve occasional powder-flow blockages.
Comparing individual particle shape using a microscope would be too cumbersome and slow. Clark knew with manual microscopy, “it would be difficult to see more than a handful of particles, certainly not enough to get a statistically significant sample.” When Clark discovered the FlowCam imaging particle analysis system at a conference, he knew he’d found his solution. Now he could get 10,000 images of individual particles in less than a minute.
The FlowCam technology uses digital imaging for measuring size and shape of microscopic particles in a fluid medium. Using the FlowCam, Clark quickly proved that particle morphology was not the same from batch to batch. Particle analysis methods typically used throughout the dry products industry do not measure shape, only size. So while Clark's product met all required specifications, he was able to optimize flow by also monitoring particle shape with the FlowCam.
This is significant because pneumatically conveyed particles of different shapes flow differently. “Most people just don’t know enough about how particle morphology affects product performance or flow characteristics to ask the question,” Clark said. “Seeing digital images of individual particles on the FlowCam provided the documentation I needed to prove what was happening.”
Clark’s questions about the effect particle shape had on particle flow through the powder educator would have been nearly impossible to answer via traditional microscopy.
See the FlowCam in Action
This quick video reviews how the FlowCAM works and acquires particle data.