Ra: roughness average or CLA, Centre line average. If Rmax is the value of maximum peak of the profile, then can you please explain the difference between Rmax and Rp.
Hi Arjun. Speaking for myself, I hate questions about surface profile because I never remember enough of the minutia and I have to keep looking it up and re-checking it; plus, it's impossible to explain what the abbreviations mean unless the questioner has a good grounding in the topic anyway :- To draw a distinction between two scales like Rmax and Rp -- as you are asking us to do -- requires a good understanding of what a sample length is and what an evaluation length is; none of the surface profile scales has any real meaning without that understanding.
As always, your comments are highly appreciated Jeffrey. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. It is therefore only suitable for evaluating the function of workpiece surfaces in combination with other surface parameters described here.
Maximum roughness depth Rmax The individual depth Rzi is the sum of the height of the largest profile point and the depth of the deepest profile of the roughness profile R within a single measuring section lr.
The maximum roughness depth Rmax is the largest individual roughness depth within the total measuring section. Rmax is a measure of the surface roughness perpendicular to the test surface.
It may be used — as is the average roughness depth Rz — to replace the roughness Rt, which is no longer used today. Measuring instruments for surface measurement can be found here: Mobile roughness measuring units PC-based roughness measuring units Automatic roughness and contour measuring units Optical measuring units.
International website EN. Current measuring technology topics - Join the conversation! Surface measurement: Selecting the correct filter. Surface measuring unit: MarSurf PS Selection of the cut-off wavelength. At this stage, there is no plan to describe instruments characteristics or calibration as this was included in ISO parts 60x and 70x, as well as parts 7x for material measures and softgauges.
But current discussions may lead to new documents. Principles have been discussed in at the Helsinki meeting and a first draft of Part 2 was established by a task force within the group.
The current drafts have reached DIS stage in Spring Voting comments will be discussed in September and the FDIS stage could be launch by the end of the year, with an official publication mid After the publication of this 3-parts standard, the old profile standards will probably be canceled ISO , , , , , This standard today is more in line with ISO standards than the previous versions, except for some differences.
The main difference is about sampling length and averaged parameters. In ASME, all profile parameters are defined and calculated on the evaluation length. It also reintroduces the parameter Rmax that was once part of ISO and is a good complement to Rz.
This standard defines special parameters for the evaluation of periodic surfaces, especially in the field of mating surfaces. It is usually referred to as Dominant waviness. It defines three parameters calculated after a special zero bandpass filter :.
These parameters are part of the Automotive module. This internal standard provides methods and parameters to analyze lead-reduced dynamic sealing surfaces.
0コメント