Laser-based apparatus and method for measuring agglomerate concentration and mean agglomerate size
AssigneeProcess Metrix
InventorDonald John Holve
Life of this patent
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Abstract
Apparatuses, methods, and systems for measuring mean particle size and concentration of a polydispersion of agglomerates are disclosed. In one embodiment, the apparatuses include a light source; a focusing lens to form a probe volume; a first light detector positioned at a first angular position from the beam of light; and a second light detector positioned at a second angular position from the first direction of the beam of light, the mean particle size and concentration being determined using nearly invariant functions of a ratio of the light scattered measured by the first and second detectors.
Claims20
An apparatus for measuring an average mass concentration of a polydispersed agglomerate of primary particles, the apparatus comprising:
- a first light source configured to emit a first beam of light in a first direction said first beam of light having a first wave length;
- a light detector configured to generate a signal related to light scattered onto the light detector by the polydispersed agglomerate in a first probe volume formed in the first beam of light;
- and
- a calculating device to calculate the average mass concentration of the polydispersed agglomerate of primary particles based at least in part on the signal generated by the light detector, wherein the calculating device is configured to calculate a Cm#(qdgo) and an average mass concentration of the polydispersed agglomerate, Cm, per unit total scattered light, PTθ, based on an equation given by:
- C
- m
- P
- T
-
-
- θ
- =
- f
- 1
-
- f
- 2
-
- C
- m
-
- #
-
- (
- qd
- go
- )
- ,
- where f1 is a function of optical properties of the primary particles, f2 is a function of a configuration of the apparatus, q is a scattering wave vector at a mean scattering angle, θ, for the optical receiver element given, in terms of the first wave length, by (4π/λ)sin(θ/2), and dgo is an average gyration diameter for an assumed size distribution for the polydispersed agglomerate.
The apparatus according to clam 6, wherein a mean size of the polydispersed agglomerate ranges from about 60 to about 1000 nm.
Dependencies are inferred from the claim text.