basic DAQ question

[SiPHER]

Hi, I have a basic DAQ question - sorry it may sound silly ... 

If I am using an optical chopper and a lock-in amplifier (LIA), say optical chopper is working at 3kHz. At the output end of LIA, may I use a sampling rate higher than 3kHz? for example, may I use a DAQ card at 300kHz to  read it? Will it cause any problem (such as accuracy, precision etc)?

Thanks.

sipher

[AnalogKid2DigitalMan]

You can sample it at 300KHz if you like, it will just create more data. If your signal has no frequncy components higher than 3KHz, then you need to sample at least 2 times that (6Khz) to satisfy the Nyquist criteria to generate an accurate representation of the signal (to prevent aliasing). Personally, if the application permits, I sample at a 5 to 10X rate.