Particle size calculated using TEM is given along with standard deviation. Is error bars in particle size determination is standard deviation? Please help me to give the error bars in particle size determination using absorption onset.
Hi,
from TEM images, you typically take a number of single particles (let's say 100) and measure their diameter (in case of spherical particles) or length and width (in case of elongated particles) or whatever. Then you make a histogram of the measured dimensions, which normally should yield a gaussian distribution with well-defined mean value and standard deviation.
In case of absorption measurements, lets say on a solution of nanoparticles, you measure billions of particles that are diluted in your solution. Hence, this measurement gives you automatically an average over a large amount of particles, but information about the size distribution is not accessable.
Hi,
One of the ways to determine the size distribution is using imageJ and plot a histogram based on the data from the imageJ (in this case diameter of the QD particles). ImageJ software provides the SD of the particle based on the sizes of the particle.
Once one make histogram plot, we can fit the plot, normally Gaussian fit as explained by Sebastian. Once one fitted plot, software provides parameter such as average size, SD etc. Yes, people normally use SD as an error bar.
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