Truncation

Truncation: This technique causes part of the time series, from a given time onward to be set to zero. For convenience Mnova truncates the time series after a given number of acquired points.  The user may access this function either via the menu 'Processing/More Processing' menu:

This technique may be used to shorten the acquisition data time series. If the FID, for example, decays to zero in 0.5 seconds and the acquisition time was 2 seconds, the FID consists of 25% signal and 75% noise.  Since both 0 and a 90 degrees phase shifted spectra are collected a time series data length of twice the FID time is required for maximum information content.  Truncating the FID at about 1.0 second will reduce the amount of storage required with no data loss. At a later time Zero Filling may be used to cosmetically adjust the spectrum's appearance.

This tool is used when the acquisition time has been set much longer than the FID, resulting in the acquisition of a long period of signal-free noise. Truncation sets the signal free latter region of the time-series to zero. This does NOT amount to zero-filling, and the appending of zero-s to twice the original number of acquisition points will still reveal the intrinsic resolution.

Here you can see an example of truncated FID: