Instruments can fail mechanically and when they do fail, it is important to recognize the signs. For NMR data, any irregularities in the baseline can indicate an instrument issue. The best strategy to minimize instrument failures is to perform regular maintenance and collect data for standards with well documented results prior to any data collection.
The legs used to support the NMR magnet are cushioned by lifts to reduce excessive floor vibrations. If one of the lifts is not performing as it should, then the acquired data will exhibit some vibrational noise. The noise can affect the analysis of the data.
Below are two 1H NMR spectra for the same sample magnified by a factor of ten. The spiky baseline (somewhat symmetrical too) in the top spectrum is a result of a malfunctioning lift on one of the legs. The bottom spectrum does not exhibit these spikes; it was collected from the same NMR instrument with the same sample under identical conditions but the lift was repaired.
For the case where all the legs’ lifts are disabled, Glenn Facey’s blog shows the resulting spectrum.
I would like to give a special thanks to Kent for proposing the idea.