11
3 dB Frequency
100 Hz
300 Hz
1 kHz
10 kHz
20 kHz
50 kHz
10 % Frequency
70 Hz
200 Hz
700 Hz
7 kHz
14 kHz
35 kHz
The slope of the low pass filters is 40 dB per decade.
180°
-180°
-90°
90°
0
0,1
1
10
100
kHz
0 dB
-20 dB
-40 dB
0,1
1
10
100
kHz
1 kHz
1 kHz
10 kHz
10 kHz
20 kHz
50 kHz
20 kHz
50 kHz
180°
-180°
-90°
90°
0
0 dB
-20 dB
-40 dB
10
100
1000
10000
Hz
10
100
1000
10000
Hz
100 Hz
300 Hz
100 Hz
300 Hz
Fig. 6: Typical frequency and phase response of the low pass filters
High Pass
The M68 signal conditioners have a high pass filter with
a lower limiting frequency of 3 Hz (-3 dB). By means of
this filter low frequency noise can be removed. Low
frequency noise may occur, for example, by the influ-
ence of temperature transients to piezoelectric compres-
sion type accelerometers. The slope of the 3 Hz high
pass filter is 40 dB / frequency decade (Fig. 7). The
3 Hz high-pass filter is switched on by turning the
“INTEGRATOR HIGH PASS” switch into position
“ACC 3 Hz”. If the high pass filter is switched off
(switch position “0.1 Hz ACC”), the lower limiting
frequency of the amplifier is 0.1 Hz.
)
)
)
)
When using the integrators, the 3 Hz high pass filter is
switched on in any case.
