Denkmalgeschützte Bauwerke im Clouth Quartier
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| Bereich | Geometrische Produktspezifikation (GPS) | ||
| Titel | Surface texture : areal | ||
| Kurzbeschreibung: | Geometrische Produktspezifikation, flächenhafte Oberflächenparameter | ||
| Letzte Ausgabe | 2007 | ||
| Übernahme von | ISO 25178 | ||
Die Norm ISO 25178 mit dem vollständigen Titel „Geometric Product Specifications (GPS) – Surface texture : areal“ (deutsch: „Geometrische Produktspezifikation (GPS) – Oberflächenbeschaffenheit: Flächenhaft“) ist eine Sammlung internationaler Normen zur Analyse von 3D-Oberflächentexturen.
Diese Norm wurde vom Technischen Komitee TC213 der Arbeitsgruppe WG16 der ISO (Internationale Organisation für Normung) erarbeitet.
Es ist die erste internationale Norm die Messung und Spezifikation von 3D-Oberflächentexturen berücksichtigt. Im Einzelnen definiert die Norm 3D Texturparameter und die zugehörigen Operatoren zu deren Bestimmung. Sie beschreibt auch die anwendbare Messtechnik, Kalibriermethoden und physikalische Kalibrierstandards, sowie die dafür nötige Kalibriersoftware.
Eine grundlegend neuer Bestandteil der Norm ist die Abdeckung der Berührungslosen Messmethoden, die zwar schon weit in der Industrie verbreitet sind, denen aber bisher eine Norm fehlte um Qualitätsaudits nach ISO 9000 durchzuführen. Die Norm führt zum ersten mal 3D Oberflächencharakterisierung in Bereiche ein, in denen die 2D-Profilometer seit über 30 Jahren durch Normen standardisiert wurde. Das gleiche gilt für die damit verbundene Oberflächenmesstechnik, die nicht auf mechanisch abtastende Verfahren beschränkt ist, sondern auch Konfokalmikroskope oder Interferometer umfasst.
Aufbau der Norm
Bearbeiten<-- übersetzung bis hier -->
Documents constituting the standard
Bearbeiten- Part 1: surface texture indications
- Part 2: terms, definitions and surface texture parameters
- Part 3: specification operators
- Part 6: classification of methods for measuring surface texture
- Part 601: nominal characteristics of contact (stylus) instruments
- Part 602: nominal characteristics of non-contact (confocal chromatic probe) instruments
- Part 603: nominal characteristics of non-contact (wavefront interferometric microscope) instruments
- Part 701: calibration and measurement standards for contact (stylus) instruments
Other documents are in draft or being drafted and will been published in the next few years. A number of documents that are in draft concern, in particular, other optical measurement technologies (3D confocal microscope, white light interferometric microscope, digital holographic microscope).
New definitions
BearbeitenThe ISO 25178 standard is considered by TC213 as first and foremost providing a redefinition of the foundations of surface texture, based upon the principle that nature is intrinsically 3D. It is anticipated that future work will extend these new concepts into the domain of 2D profilometric surface texture analysis, requiring a total revision of all current surface texture standards (ISO 4287, ISO 4288, ISO 1302, ISO 11562, ISO 12085, ISO 13565, etc.)
A new vocabulary is imposed:
- S filter: filter eliminating the smallest scale elements from the surface (or of the shortest wavelength for a linear filter)
- L filter: filter eliminating the largest scale elements from the surface (or of the longest wavelength for a linear filter)
- F operator: operator suppressing nominal form.
- S-L surface: surface obtained after S and L filtering. Equivalent to a roughness or waviness surface.
- S-F surface: surface obtained after S filtering and application of the F operator.
- Primary surface: surface obtained after S filtering.
- Nesting index: index corresponding to the cut-off wavelength of a linear filter, or to the scale of the structuring element of a morphological filter.
The new authorized filters are described in the series of technical specifications included in ISO/TS 16610. These filters include: the Gaussian filter, the spline filter, robust filters, morphological filters, wavelet filters, cascading filters, etc.
3D areal surface texture parameters
BearbeitenGeneralities
Bearbeiten3D parameters are written with the capital letter S (or V) followed by a suffix of one or two small letters. They are calculated on the entire surface and no more by averaging estimations calculated on a number of base lengths, as is the case for 2D parameters. In contrast with 2D naming conventions, the name of a 3D parameter does not reflect the filtering context. For example, Sa always appears regardless of the surface, whereas in 2D there is Pa, Ra or Wa depending on whether the profile is a primary, roughness or waviness profile.
Height parameters
BearbeitenThese parameters quantify the z axis perpendicular to the surface only.
| Parameter | Description |
|---|---|
| Sq | Root mean square height of the surface |
| Ssk | Skewness of height distribution |
| Sku | Kurtosis of height distribution |
| Sp | Maximum height of peaks |
| Sv | Maximum height of valleys |
| Sz | Maximum height of the surface |
| Sa | Arithmetical mean height of the surface |
Spatial parameters
BearbeitenThese parameters quantify the lateral information present on the x and y axes of the surface.
| Parameter | Description |
|---|---|
| Sal | Fastest decay auto-correlation rate |
| Str | Texture aspect ratio of the surface |
| Std | Texture direction of the surface |
Hybrid parameters
BearbeitenThese parameters combine the information present on the x, y and z axes of the surface.
| Parameter | Description |
|---|---|
| Sdq | Root mean square gradient of the surface |
| Sdr | Developed area ratio |
Functional parameters
BearbeitenThese parameters are calculated from the Abbott-Firestone curve obtained by the integration of the height distribution on the whole surface.
| Parameter | Description |
|---|---|
| Smr | Surface bearing area ratio |
| Smc | Height of surface bearing area ratio |
| Sxp | Peak extreme height |
| Vm | Material volume at a given height |
| Vv | Void volume at a given height |
| Vmp | Material volume of peaks |
| Vmc | Material volume of the core |
| Vvc | Void volume of the core |
| Vvv | Void volume of the valleys |
Parameters related to segmentation
BearbeitenThese parameters are derived from a segmentation of the surface into motifs (dales and hills). Segmentation is carried out using the watersheds method.
| Paramètre | Description |
|---|---|
| Spd | Density of peaks |
| Spc | Arithmetic mean peak curvature |
| S10z | 10 point height |
| S5p | 5 point peak height |
| S5v | 5 point valley height |
| Sda | Closed dales area |
| Sha | Closed hills area |
| Sdv | Closed dales volume |
| Shv | Closed hills volume |
3D surface texture measurement instruments
BearbeitenPart 6 of the standard divides the usable technologies into three families:
- Topographical instruments: contact and non-contact 3D profilometers, interferential and confocal microscopes, structured light projectors, stereoscopic microscopes, etc.
- Profilometric instruments: contact and non-contact 2D profilometers, line triangulation lasers, etc.
- Instruments functioning by integration: pneumatic measurement, capacitive, by optical diffusion, etc.
and defines each of these technologies.
Next, the standard explores a number of these technologies in detail and dedicates two documents to each of them:
- Part 6xx: nominal characteristics of the instrument
- Part 7xx: calibration of the instrument
Contact profilometer
BearbeitenParts 601 and 701 describe the contact profilometer, using a diamond point to measure the surface with the assistance of a lateral scanning device.
Chromatic confocal gauge
BearbeitenPart 602 describes this type of non-contact profilometer, incorporating a single point white light chromatic confocal sensor. The operating principle is based upon the chromatic dispersion of the white light source along the optical axis, via a confocal device, and the detection of the wavelength that is focused on the surface by a spectrometer.
References
Bearbeiten- ISO 25178 on the ISO Web site
- New 3D parameters and filtration techniques for surface metrology, François Blateyron, Quality Magazine White Paper
- ISO 25178 – new family of 3D feature parameters characterises topographical surface features, François Blateyron, Surface Newsletter
- ISO/TS 16610-1 : Geometric Product Specifications (GPS): Filtration – Part 1: Overview and basic concepts
- ISO/TS 14406 : Geometric Product Specifications (GPS): Extraction