Mitutoyo SURFTEST SJ-410 - Filters

23. REFERENCE INFORMATION
No. 99MBB765A
23-9
23.2.2 Filters
■ Types of filters
The following 3 types of filters are available.
Filter
Amplitude characteristics
Phase characteristics
Amplitude transmission at the cut-off value
2CR 2CR Without phase
correction
75%
PC75 2CR Phase correction 75%
GAUSS Gaussian Phase correction 50%
The characteristics of each filter are explained below.
The attenuation characteristic of each filter is represented by the characteristics of a
high-pass filter.
• 2CR
This filter has the same attenuation characteristic as 2 C-R circuits that are connected
in series and that have identical time constants.
The attenuation characteristic is -12 dB/oct, and the amplitude transmission at the
cut-off value is 75%, as shown in figure below.
Attenuation characteristic of 2CR filter
Attenuation characteristic:
( )
2
3
1
1








+
=
c
H
λ
λ
λ
Amplitude transmission (%)
Amplitude transmission (dB)