Re: Mean diameter

[Nirendra Mustafi]

Hello everybody!

I wonder if there is any way to determine the 'mean diameter' of a
particle or an agglomerated particle (which will have a very irregular
shape). I'm using ImageJ to analyze the images taken from SEM for diesel
engine exhaust particles. I can use 'analyze particles' tool to count
and quantify the areas and ellipses can be fitted on to them or
'projected area diameter' from the areas easily.

With regards and thanks in advance for your help
--
##########################################
Nirendra Nath Mustafi
Thermodynamics Lab.
Mechanical Engineering Department
The University of Auckland
Private Bag 92019
Auckland, New Zealand
Ph.: [phone] Ext 87007 (Work)
        [phone] (Home)
Fax: [phone]
E-Mail: [hidden email]

[Gabriel Landini]

On Sunday 04 February 2007 21:46:02 Nirendra Mustafi wrote:
> I wonder if there is any way to determine the 'mean diameter' of a
> particle or an agglomerated particle (which will have a very irregular
> shape). I'm using ImageJ to analyze the images taken from SEM for diesel
> engine exhaust particles. I can use 'analyze particles' tool to count
> and quantify the areas and ellipses can be fitted on to them or
> 'projected area diameter' from the areas easily.

How do you define "mean diameter"?
I imagine that the mean diameter of the letter "C" must be quite different
from the letter "O" (i.e. convex vs. concave objects) so this must depend on
how one defines the diameters (passing from the centre of mass, from the
centroid, rotating particle, inscribed circles, (max+min)/2, etc.).

Cheers,

Gabriel