|
Particle Size Class |
Size x in µm |
|---|---|
|
B |
5 ≤ x < 15 |
|
C |
15 ≤ x < 25 |
|
D |
25 ≤ x < 50 |
|
E |
50 ≤ x < 100 |
|
F |
100 ≤ x < 150 |
|
G |
150 ≤ x < 200 |
|
H |
200 ≤ x < 400 |
|
I |
400 ≤ x < 600 |
|
J |
600 ≤ x < 1.000 |
|
K |
1.000 ≤ x < 1.500 |
|
L |
1.500 ≤ x < 2000 |
|
M |
2.000 ≤ x < 3.000 |
|
N |
3.000 ≤ x |
1. Particle Concentration Classification
Depending on the normalization parameter the particle count per size class is expressed in cleanliness level as shown in the table:
|
Cleanliness Level |
Particle Count |
|---|---|
|
00 |
0.00 |
|
0 |
1.00 |
|
1 |
2.00 |
|
2 |
4.00 |
|
3 |
8.00 |
|
4 |
16.00 |
|
5 |
32.00 |
|
6 |
64.00 |
|
7 |
130.00 |
|
8 |
250.00 |
|
9 |
500.00 |
|
10 |
1000.00 |
|
11 |
2000.00 |
|
12 |
4000.00 |
|
13 |
8000.00 |
|
14 |
16000.00 |
|
15 |
32000.00 |
|
16 |
64000.00 |
|
17 |
130000.00 |
|
18 |
250000.00 |
|
19 |
500000.00 |
|
20 |
1000000.00 |
|
21 |
2000000.00 |
|
22 |
4000000.00 |
|
23 |
8000000.00 |
|
24 |
16000000.00 |
|
> 24 |
∞ |
2. Normalization
The absolute particle number is divided by a normalization factor:
- Number of components N
- Wetted component area A or
- Wetted component volume V
Number of Components (N)
absolute number of particles / component number = normalized particle numbers
Result expression: normalized particle numbers
Wetted component area (A) in mm2
absolute number of particles / wetted component surface and normalization to standard area:*1000 cm2
Result expression: normalized cleanliness code
Wetted component volume (V) in cm3
absolute number of particles / wetted component surface and normalization to standard area*100 cm3
Result expression: normalized cleanliness codes
Example:
The cleanliness codes always refer to normalized and standardized particle results.
- Number of components = 10
- Wetted component Area = 200 cm2
- Wetted component Volume = 50 cm3
Method: Standard Analysis
The standard analysis is fully parameterized from component extraction to filter analysis.
Advantages: The standard analysis has a good degree of result compatibility and is system and operator independent. No further agreement between customer and supplier is required.
|
Parameter |
Description |
|---|---|
|
Measurement of |
Length and/or width ≥ 50 µm |
|
Length |
Feret Max |
|
Width |
Feret Min |
|
Relative image brightness |
50 - 60%. Default value: 55% |
|
Relative threshold |
70% |
|
Particle typification |
Metallic shine as option (Multi Channel 90°/135°) |
|
Contrast |
Polarized light |
|
Particle type class All does exclude fibers by default. |
|
|
Specific fiber criterion based on elongated fiber length and maximum inner circle |
|
|
Calculation on complete measurement area (effective filter diameter) |
|
For more information, see Concept of Relative Image Brightness and Relative Threshold.
Method: Extended Analysis - Free Analysis
The extended analysis - free analysis is applied whenever supplementary particle information is required:
- Smaller particle size classes
- Particle height measurement
Any changes from the standard method must be documented in detail. You can use the extended analysis with the scope of the following:
- Cause study for critical particles
- Process optimization
- Cleanliness specification beyond standard analysis, for example smaller size classes or 3rd dimension.
|
Parameter |
Description |
|---|---|
|
Measurement of particles |
Length and/or width ≥ 5 µm |
|
Length |
Feret Max |
|
Width |
Feret Min |
|
Individual relative image brightness |
50 - 60%. Default value: 55%. Can be defined individually. |
|
Individual relative threshold |
70%. Can be defined individually. |
|
Particle typification |
Metallic shine as option (Multi Channel 90°/135°) |
|
Contrast |
Polarized light |
|
Particle type class All does exclude fibers by default. |
|
|
Specific fiber criterion based on elongated fiber length and maximum inner circle |
|
|
Calculation on complete measurement area (effective filter diameter) |
|
Default Values for Particle Typification
|
Parameter |
Description |
|---|---|
|
Metallic-Shiny |
(Mean gray value > 200.0) or (Max. gray value ≥ 240.0) |
|
Non-Shiny |
Objects which are not fiber and not metallic-shiny. |
|
Fiber |
(Max. Inscribed Circle ≤ 50.0) and (Fiber Length/Max. Inscribed Circle > 20.0) |
As a Supervisor, you can edit the values in the Standard Template Editor, see Standard Template Editor.
Occupancy Rate
The occupancy rate is a measurement value to describe the quality of the specimen preparation in terms of particle density, and the distribution of particles on the effective filter area. The calculation is performed as follows:
Sum of the particle area of all detected particles in relation to measurement frame area. Value in %.
For more information, see
- About Filters and Occupancy Rate
- Occupancy Rate (Components) Tool
3. Core parameter for size class distribution
Length = Feret Max (default use case), see Feret Maximum
Width = Feret Min (default use case), see Feret Minimum
Maximum inscribed circle = The largest circle that can be inscribed inside an area, see Diameter Maximum Inscribed Circle Filled
Fibers, see Fiber Length