After HyperLab's spectrum peak evaluator determined the position and the area of the peaks, it creates a peak list, where the peak centroids are shown both in channel and in energy (keV) unit. The energy values are calculated from the fitted channel values by utilizing the energy calibration function, which performs this transformation.
HyperLab's energy calibration function is different from most competitors' solution: it uses a simple linear channel – energy function with an optional additive nonlinearity function.
When nonlinearity is not used, energy values in keV are computed from the channel values with the following formula:
When nonlinearity correction is in effect, the formula changes to the following:
This second formula contains the NonlinShift parameter, which is computed from the system's nonlinearity curve.