09-07-2015 03:04 PM
Mari,
There is no way, theoretically or practically, to reliably identify aliased signals. Sometimes, when the frequency of the signal which creates the alias is precisely known you can calculate where the alias would appear. Even then it is impossible to separate that component from any portion of the real signal which appears at that frequency.
If you think there is a possibility of aliasing the only real fix is an external hardware anti-aliasing filter.
Lynn
03-13-2020 11:36 PM
I used NI 9201 as my DAQ card to read my piezoelectric sensor (unimorph). my cut off frequency is supposed to be 500 HZ but could not insert the value in the filter (as it already mentioned that it has default only 400 HZ). and it keep appearing in my filter that " the current filter specifications do not meet the Nyquist criterion for the given input signal" . How do i solve this problem and is there any mistake with my procedure?
03-14-2020 03:50 PM
@nurfikhira wrote:
I used NI 9201 as my DAQ card to read my piezoelectric sensor (unimorph). my cut off frequency is supposed to be 500 HZ but could not insert the value in the filter (as it already mentioned that it has default only 400 HZ). and it keep appearing in my filter that " the current filter specifications do not meet the Nyquist criterion for the given input signal" . How do i solve this problem and is there any mistake with my procedure?
mcduff