Orthogonality error describes the effect of internal phase error between the sine and cosine outputs. These outputs at exactly 90 ° out of phase produces signals usable in an arctangent calculation. A non-linearity occurs if there is phase error in the outputs. This non-linearity requires more involved trigonometric transformations to correct. The error in phase is determined by comparing the zero crossing of the cosine output to the relative maximum of the sine output. Typically, this error is negligible for AMR sensors due to their construction. The method to remove a phase error, defined as β from an arctangent calculation, is shown in Equation 10.