An example of an LSD plot, for the spectrum from CFHT file 1822453pn.s. The lower curve is the mean Stokes I spectral line, with the primary star at −45 km s^-1 and the secondary at + 70 km s^-1. The lack of symmetry about the line centre of the mean primary line is clearly visible, while the secondary line is both constant in shape and symmetric. The upper curve is the mean Stokes V circular polarisation, multiplied by 20 and shifted upward to + 1.04 for ease of comparison. This Stokes component clearly shows that a field is present in the primary, while no evidence of a field is seen in the secondary.