What is "Cut off Length" in Surface roughness tester

[psavijay]

Could anybody explain What is Cut off Length in Surface roughness testing instruments and what is it's effect on measurement with respect to various cut off lengths

[Jim Wynne]

Originally Posted by psavijay

Could anybody explain What is Cut off Length in Surface roughness testing instruments and what is it's effect on measurement with respect to various cut off lengths

Cutoff length refers to the distance a profilometer stylus travels across a surface when taking a measurement. In general, the shortest distance that provides uniform results is best.

[Claes Gefvenberg]

Originally Posted by psavijay

and what is it's effect on measurement with respect to various cut off lengths

You can find advice on how to choose cut-off length in ISO 4288, Geometrical Product Specifications (GPS) -- Surface texture: Profile method -- Rules and procedures for the assessment of surface texture.

Usually, an evaluation length equal to five consecutive cut-off lenghts provides a good result.

/Claes

[psavijay]

Hi

thanks Now I understand Cut off length is equal to a sampling length and Evaluation length is equal to n*sampling length.
I am happened to use Mitutoyo SJ 400 and finally I got the user manual

[Claes Gefvenberg]

Originally Posted by psavijay

Now I understand Cut off length is equal to a sampling length and Evaluation length is equal to n*sampling length.
I am happened to use Mitutoyo SJ 400 and finally I got the user manual

Great. I always find it commendable when people find out about the inner workings of the equipment they use instead of just running it and accepting the output.

/Claes