The Analysette 22 NanoTec is the first Particle Size Analyzer that combines Particle Shape Analysis by laser diffraction.
Shape recognition of particles with the Analysette 22 NanoTec
- The recognition of the shape of particles is possible on the basis of diffraction structures.
- The diffraction pattern created by the particles in the laser contains information about the shape of the particles.
- Different shapes of particles create different diffraction patterns in the laser beam.
- Information on the shape can be extracted from appropriate methods of signal processing.
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Figure 1: diffraction pattern of a sphere-shaped particle |
Figure 2: diffraction pattern of an ellipsoid particle |
For real measurement, however, there are several particles in the volume to be measured - with arbitrary alignment in the room and with varying particle sizes.
The resulting diffraction pattern now contains combined information about the particle size, spatial arrangement and particle shape (figure 3).
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Figure 3: diffraction pattern of a particle collective |
Using a new type of sensor (figure 4) it is possible to record the areas of the diffraction pattern in which the information about the shape of the particles is contained.
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Figure 4: Drawing of the sensor arrangement |
To evaluate the sensor data, a simulated neuronal back propagation network was trained and used.
With this, a calibration of shape is received which is to a large degree independent of the material which is displayed in the diagram (figure 5).
Investigations have shown that the values measured, averaged over a certain number of measurements agree to a large extent with the desired values.
Sensor Data
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Legend
Calculated Value
Nominal Value
Sliding Average |
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Figure 5: Comparison of prescribed particle elongation with sensor data measured. |
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Particle shape analysis rev. April