How is profile of a surface measured?
Profile is usually measured using a CMM due to the complexity of some of the surfaces that are called out. The CMM would compare the 3D scan of the profile to the dimensions called out on the drawing to see if it was in spec.
Does surface profile need a datum?
Profile can control, form, location, orientation, and size or any subset of these. Profile can be used with or without datum references and with or without basic dimensions.
What is a surface profile?
Surface profile is defined as a measurement of the maximum peak-to-valley depth generated by abrasive blast cleaning and impact-type power tools. These operations effectively increase the surface area and provide an “anchor” for the applied coating system.
What is the measurement of a surface?
Surface measurement, also known as surface metrology – refers to the measurement of topography or surface roughness of precision surfaces. Surface roughness and the details of the surface profile determine the performance and appearance of many products.
How do you measure surface accuracy?
The most common method is to use a diamond stylus profilometer. The stylus is run perpendicular to the lay of the surface. The probe usually traces along a straight line on a flat surface or in a circular arc around a cylindrical surface. The length of the path that it traces is called the measurement length.
What is difference between straightness and flatness?
Flatness vs straightness Flatness is the 3D equivalent of the surface straightness control. While straightness has parallel lines representing its tolerance zone, the flatness tolerance zone is formed by two parallel planes.
What is difference between parallelism and flatness?
When you call out parallelism, flatness is implied (you are measuring a surface variation between two parallel planes = flatness) However the biggest difference is parallelism is measured with respect to a datum, ensuring both the datum and reference feature are always parallel.
What is surface profile in GD?
The surface profile tolerance zone consists of two parallel planes, bilaterally disposed on each side of the ideal curved surface (aka the true profile). Both planes follow the shape of the ideal surface and the distance between them is the tolerance limit for the callout.
Can a surface profile be a datum?
This surface acts as the primary datum in terms of how the part will seat/mate functionally in the assembly. My intent is to identify this surface as Datum A with a profile tolerance which is essentially creating a virtual condition boundary for the form of the feature.
What is the difference between surface profile and surface profile tolerance zone?
In other words, while profile of a line looks only at a specific cross section, profile of a surface looks at how measurements vary from one cross section to the next. The surface profile tolerance zone is the range that falls within two parallel curves following along the contour of the surface profile across the entire length of the surface.
What is the difference between a line and a profile?
With profile of a line vs. profile of a surface, the former controls variation at specified cross sections while the latter controls the entire feature surface. As important as inspections are, 100% inspection requires time and cost without a guarantee of 100% compliance.
What is the definition of surface profile?
The determination of surface profile depends on its definition. ISO 1 8503-1 2 defines it as the height of the major peaks relative to the major valleys. ASTM 3 D7127 4 describes it as the positive and negative vertical deviations measured from a mean line, approximately the center of the profile being evaluated.
What is the best surface profile measurement method?
It is not surprising then that it has arguably become the most popular field method for measuring surface profile. Replica tape consists of a layer of compressible foam affixed to an incompressible polyester substrate of highly uniform thickness (2 mils +0.2 mils 9 ).