A notch filter is typically an aggressive filter that strongly attenuates the power over a narrow region of the spectrum. For example, a notch filter at 60 Hz / 50 Hz is used to filter out power line noise with minimal disruption to the rest of the signal.
All MP biopotential amplifier modules which contain a 50/60 Hz notch filter only engage the filter when the pass filter is also ON:
For amplifiers with a 35 Hz LPN low pass notch filter setting (ECG, EEG, EOG): the 50/60 Hz notch is only engaged when this filter is ON.
For amplifiers with a 100 Hz HPN high pass notch filter setting (EMG, ERS): the 50/60 HZ notch is only engaged when this filter is ON.
Plots of the frequency responses of these filters may be found in an Appendix in the MP Systems Hardware Guide (also available via the “Help” menu in AcqKnowledge).
Page last modified 31Dec2014