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9.1.1 Terms
Filtering profile: The original profile after removing the waviness components via the roughness filter.
Direct profile: Original profile only after calculating of the center line using least squares method.
RC: Traditional second-order RC filter, in line with the old standard. There are still some users for it, so it is
available for the instrument as a transition. There is a phase difference between the input signal and output signal
of the filter.
PC-RC: A filter based on the RC filter after a digital phase correction. The amplitude transmission characteristic is
the same as the RC filter, basically no phase difference. The amplitude parameters obtained from the RC filter and
PC-RC filter are the same.
GAUSS (Gaussian filter): The latest roughness filter, in line with GB/T 18777-2002 Geometrical product
specifications (GPS) - Surface texture - Profile method - Metrological characteristics of phase correct filters.
9.1.2 Traversing length
●
RC Filter
●
PC-RC Filter
●
GAUSS Filter
Traversing length
Approach
travel
0.5mm
Pre-travel
Assessment length
lr
×
n
Origin
End
Pre-travel
lr
Assessment length
lr
×
n
Post-travel
lr
Traversing length
Origin
End
Approach
travel
0.5mm
l
=
λ
c
Pre-travel
lr/2
Post-travel
lr/2
Traversing length
Origin
End
Approach
travel
0.5mm
Assessment length
lr
×
n
