NMR Panopticum: DC Offset of the FID

A constant voltage offset of the FID in the real or imaginary part will cause a "peak" exactly in the middle of the spectrum.

How to avoid?

• calibrate the ADC channels
• or perform an offset correction before Fourier transformation

You will find more information on my page on processing, where I describe how to remove the dc offset.

This is a Cd-113{H-1} NMR spectrum, where I actually exaggerated the effect.