The appropriate sampling rate setting depends on the frequency range present in the signal to be measured. If the sampling rate is too low, information is irreversibly lost and the original signal will not be represented correctly in LabChart. If the sampling rate is too high, no information is lost, but the excess data increases processing time and may give excessive noise in the signal or result in unnecessarily large LabChart data files. The Nyquist Theorem states that an analog signal can be digitized without aliasing error if and only if the sampling rate is greater than or equal to twice the highest frequency component in a given signal. However, using a sampling rate 3-4 times higher than the highest frequency component expected in the signal is a good general rule for choosing the sampling rate for a recording. Please note, changing a waveform’s on-screen display (by enlarging it in the Zoom window or by stretching or shrinking its Time axis, for instance) does not affect its sampling frequency, just its appearance.
To learn more about how to choose the appropriate sampling rate and range settings in LabChart, please review the instructional guide located HERE.
For further technical assistance with this or any other issue, please contact ADInstruments Technical Support by clicking HERE.