20. The Profile Graph

Trying to understand surface texture using just a parameter or two is like trying to drive at night using only your speedometer and a compass. Those tools can tell you which direction you’re headed, and how fast…but they can’t help you to correct. The situation is the same in the world of surfaces: a number … Read more

19. The Probability Parameters

Sanding a wood project — it makes a beautiful final finish (even if it takes a lot of work to get there!) A plateaued surface finish is similar to a sanded wood finish: we start with a rough process that creates the valley regions, then we go back over it with a finer process to … Read more

18. The Gaussian Filter

When you’re driving, your tires, shock absorbers, and suspension remove most of the harsh vibrations from the road. In surface texture analysis, filtering has much the same effect: separating larger “waviness” structures from the finer “roughness.” The most common filter type is the Gaussian filter, which acts like the perfect shock absorber in terms of … Read more

17. Measurement Settings

The measurement settings for roughness gages can be intimidating. There are a lot of options, and it’s not always clear what they do. In this video we make it easy for you as we point out the two most important settings: the wavelengths which define “roughness” (filtering and cutoffs), and the length of data we … Read more

16. Why Use a Skid?

To measure surface roughness, a roughness gage (sometimes called a stylus profilometer) traces a small stylus over the surface. A stylus on its own can be very sensitive to not only the surface but also to outside influences. Any vibration or disturbance can make it move, which will introduce errors to the measurement. To help … Read more

15. Why Not Repeatability?

How good is my surface roughness gage? There’s an old tale of three blind people describing an elephant based on the small portions of the animal that they each experience. It’s a great analogy for surface measurements: we may get very different information about a surface just by slightly changing the measurement location. In this … Read more