ISO 12085:1996 pdf download – Geometrical Product Specification (GPS)-Surface texture: Profile method – Motif parameters
ISO 12085:1996 pdf download – Geometrical Product Specification (GPS)-Surface texture: Profile method – Motif parameters.
ISO 12085 defines terms and parameters used for determining surface texture by the motif method. It also describes the corresponding ideal operator and measuring conditions.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of pubhcation. the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 1302:1992. Technical drawings — Method of indicating surface texwre.
ISO 3274:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Nominal characteristics of contact (stylus) instruments.
ISO 4287:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions and parameters of surface texture.
ISO 4288:1996, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Rules and procedures for the assessment of surface texture.
For the purposes of this International Standard the following definitions apply.
3.1 General definitions
3.1.1 surface profile: (See ISO 4287)
3.1.2 primary profile: (See ISO 3274.)
In order to have reproducible results with existing apparatus, the method of calculation given in Al to A.3 shall be applied in the software (see figure A.1).
A.1 Profile decomposition in “segments”, the length of which is smaller than or equal to “A “for roughness and “B” for waviness (“A” and “B” values in 5.2)
Find two peaks P, P + 1 satisfying the following conditions:
— the horizontal distance between these two peaks is maximum;
— this horizontal distance is smaller than or equal to A or B (see table 1);
— there is no peak between them, higher than either of them.
The part of the profile comprised between these two peaks is called “segment”.
4.2 Motif combination inside each segment
Inside each segment, the three conditions I, Ill, IV of 4.4 are successively tested on each pair of motifs. The combination of two individual motifs is only possible if these three conditions are fulfilled.
For condition IV. the minimum (H ÷ , H + 2) is compared to 60 % of the vertical reference T of the segment (T= minimum of the two heights h1, h2 of the segment) and not to that of the possible combined motif.
When all individual motifs inside the segment have been successively tested, the combination operation is performed again from the beginning of the segment until no combination is possible inside this segment.
The following segments are then examined in the same manner.
A.3 Combination over the whole profile
All motifs resulting from the previous step are combined two by two over the whole profile. For each pair of motifs, the conditions I, ii. Ill, IV are successively tested. The two considered motifs are combined only if these four conditions are fulfilled. For condition IV. the vertical characteristic T is the minimum of the two heights of the possible combined motif considered.
When all motifs of the profile are successively tested, the combination operation is performed ag&n from the beginning of the profile until no combination is possible.