Digitisation of data

Digitisation of data during a 2D experiment is subject to the same thermal noise arising from the probe head and preamplifier as in a ID experiment, and this contributes to the noise baseplane observed in the 2D spectrum. There also exists a particularly objectionable artefact associated with 2D experiments, referred to as noise (note the here refers to the evolution period and should not be confused with the relaxation time constant). This appears as bands of noise parallel to the/i axis where an NMR resonance exists, and it is sometimes this that limits the observation of peaks in the spectrum rather than the true thermal noise. Indeed, it appears that the very earliest work on 2D NMR was unpublished due to excessive ti noise present in the spectra. Generally speaking, this is caused by... 

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