Malvern Mastersizer 3000 User Manual

Viewing measurement results Chapter 5
Mastersizer 3000 Page 5-15
 The second term is the cross-sectional area of the particle and the final term n
i
is the number of particles of radius r
i
.
In terms of the volume of particles , the equation above becomes, for
an ensemble of particles:
The size of the particles is expressed by the diameter d and the volume terms can be
separated into a relative volume distribution v and a total concentration Cv (total
volume of particles in a unit volume of dispersant). The equation then becomes:
Substituting the above into equation (1) and solving for the concentration gives:
If d is measured in m and b in mm, and v is the relative concentration of the size
distribution (such that
) then:
This equation provides the concentration in parts per million (ppm). To calculate
the value as a percentage volume concentration, the final value is divided by 10,000.
In the above equation:
 The Transmission (T) is a value between 0 and 1 and is measured directly by
the instrument.
 The particle size distribution v
i
is the relative volume in size-class i with mean
diameter d
i
.
 Q
i
- the mean extinction term for size-class i - is calculated from scattering the-
ory and is a function of the optical properties of the particle and dispersant
media.
V
i
4
3
---
r
i
3
n
i
=

i
3
4
---
Q
i
V
i
r
i
-----------

=

i
3
2
---
C
v
Q
i
V
i
d
i
-----------

=
C
v
2Ln T–
3b
Q
i
v
i
d
i
----------

------------------------
=
v
i

1=
C
v
ppm
2000Ln T–
3b
Q
i
v
i
d
i
----------

------------------------------
=

Malvern Mastersizer 3000 Specifications

General

Measurement principle	Laser diffraction
Blue laser wavelength	470 nm
Sample dispersion options	Wet and dry dispersion
Data acquisition rate	10 kHz
Particle size range	0.01 to 3500 microns
Laser type	He-Ne and solid state
Accuracy	Better than 1%
Repeatability	Better than 0.5%
Technology	Mie and Fraunhofer theories
Sample dispersion units	Hydro MV, Hydro LV, Aero S
Optical model	Mie theory
Power requirements	100-240 V, 50/60 Hz
Detector arrangement	Log-spaced array