The Relationship Between T2 and Observed Line Width

The relationship between how long we observe the signal from a particular resonance in the time domain and how narrow the resonance 

I FIGURE 3.4 Truncation error in the digitized FID (a) manifests itself as bumps, ridges, or corduroy around the base of narrow peaks in the Fourier- 

Truncation error. Regularly spaced bumps or ripples observed on either side of the narrow peaks in a frequency spectrum that are caused by the failure of the digitized FID s amplitude to fall to the level of the background noise before the end of the digitization of the FID. 

Doublet. A resonance splitting pattern wherein the resonance appears as two peaks, lines, or legs. 

Put another way, if the sinusoidal signal we detect does not persist in the xy plane long enough for the detector to accurately measure its frequency, then there will be uncertainty in the measured frequency. A resonance with an indeterminate frequency will possess a large line width in the frequency domain. (The line width of a resonance is measured at half of the peak height). A broad line corresponds to a large uncertainty in frequency. 

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