Manual ibaPADU-8-ICP
20 Issue
1.7
9.3
Low-Pass Filter
A programmable 72 dB 6-pole low-pass filter is implemented on each ICP
®
channel.
Commands sent from the ibaFOB are used to set this filter frequency.
The frequency range for the low-pass filter is 0.5 Hz …25 kHz.
Specification
Example
Range (Hz)
Accuracy
Reference (Hz)
Actual Value (Hz)
100-250 1
%
126
126,3
250-500 1
%
270
270,3
500-1000 1
%
990
990,1
1000-10000 10
%
3750
3773,6
10000-25000 10
%
21500
22222
Tip
The programmable digital filter produces modulation component frequencies with
< 72 dB of the maximum signal strength. Therefore, the analysis software should take
this into account.
Tip
At corner frequencies < 1000 Hz, reflected frequencies above 50x the corner fre-
quency are possible.
Example 1: f
c
= 100 Hz
reflected frequency band starts at 50 x 100 = 5000 Hz. A signal frequency of 5100 Hz
would be noticeable at 100 Hz.
Example 2: f
c
= 1000 Hz
reflected frequency band starts at 50x 1000 = 50000 Hz. A signal frequency of
51000 Hz would be dampened 6 dB by the static low-pass filter. This signal would be
noticeable for signal strengths above 20 dB.
If a device for low-frequency applications should be required, iba can supply a variant
of this device for sampling at 1 kHz or less, with a static low-pass filter. Please contact
iba for further details.
