VDI 2083 Part 21: Cleanroom Cleanliness

VDI 2083 Part 21; Cleanroom Technology. Cleanliness of Medical Devices in the Manufacturing Process

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	Normalized particle counts (A and V) up to including
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 counts
Result expression: normalized particle counts

Wetted component area (A) in cm²

absolute number of particles / wetted component area and normalization to standard area:*1000 cm²
Result expression: cleanliness code referring to normalized particle counts (A)

Wetted component volume (V) in cm³

absolute number of particles / wetted component volume and normalization to standard volume*100 cm³
Result expression: cleanliness codes referring to normalized particle counts (V)

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 particles	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 3^rd 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

Fibers, see Fiber Length