HgAr and Ar data looks very, very similar - both having same lines and continuum. That is surprising. Having pure Ar data would be nice, in order to avoid the continuum. At the moment we are speculating that the claimed Argon lamp is not actually Argon, but HgAr. fmadec believes that possibly long time ago he saw some Argon data which was not identical to HgAr. This ticket is to investigate this issue.