We present the influence of systematic errors due to azimuth errors of the optical elements for a MME. This ellipsometer is based on the dual rotating-compensator principle in the PC1SC2A configuration developed by Collins. The first and secondorder systematic errors have been characterized for all elements of the 4×4 normalized Mueller matrix and for the Jones matrix elements tanYpp and Dpp. We show that these errors can be eliminated by a four zone measurement technical.