Re: Cumulative Distribution/Q3
Cumulative scale is just the %age of material passing through the specific size mesh i.e. 80% of material will pass 500 micron. d90, d50 and d10 particle size can be read directly from the corresponding mesh size values on X’ ■
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ta ■
Continuous Probability Distribution,
I also had a look on the net and found sufficient statistical maths to put me off. Propability offers plenty of scope for mind bending exercises but, as I understand it, the basic approach of presenting data in the form of a 'cumulative distribution' is to indicate the proportion of particles that are less than a certain size as the reference dimension is increased from zero to the maximum particle size. ■
Re: Cumulative Distribution/Q3
Assuming Q3 is referring to "third quartile" of a normal distribution, though I am not sure about your application.
Maybe it means that 70 % of the particles are less than 106 um within 3 standard deviations or you have 99.73 % confidence (or you would expect 0.27 % may be greater than 106 um).
See following:
http://en.wikipedia.org/wiki/Standarddeviation
Regards,
Lyle ■
Cumulative distribution/Q3
Hi,
I have some data for the particle size measurement of an API powder, measured using a Sympatec, HELOS particle size analyser. The data are plotted as cumulative distribution Q3 (y axis) versus particle size (x axis). Can anyone xplain 'cumulative distribution Q3' in laymans terms please? I've searched the net, but any definitions I've found are vague or way over my head. According to the data, 70% of the particles are less than 106 um, but my colleague says that this figure shouldn't be taken as accurate. Is anyone familiar with this technique, or know where I can get some literature that would enlighten me? Thanks in advance. ■