What are Anti-Aliasing filters and why are they optional?
Anti-Aliasing filters limit the bandwidth of a data acquisition system to only frequencies less than half the sampling rate to prevent aliasing, the effects higher frequency components on the sampled data. Encore Series model 61000 input circuitry design combined with its digital sampling techniques limit the bandwidth to prevent aliasing. Our testing and that of an independent laboratory indicate the instrument does not suffer from aliasing. IEC61000-4-30 requires the input to be band limited and the model 61000 fully complies. IEC61000-4-30 does not specify how to accomplish this and does not require hardware anti-aliasing filters. However, there have been a very small number of customers who interpret this standard to require hardware anti-aliasing filters. To meet their requirements the model 61000 has optional hardware anti-aliasing filters. However, it is important to note that choosing such filters will greatly limit the transient measurement capabilities of the instrument.
