Improved determination of FID signal parameters in low-field NMR

The automatic and efficient methods presented in this work incorporate an integral exponential fit, the fit of the power spectrum Lorentz peak and two ways to determine the FID phase. When there are sufficiently many data points in the Lorentz peak, the power spectrum Lorentz peak shape fit provides a quick, simple and accurate way of determining the amplitude, relaxation time and Larmor frequency of the FID. In the measurements of this work, however, the narrow line width led to establishing a more applicable method which is based on the exponential decay of the Lorentz peak with a temporally moving power spectrum window.