Variation in magnet fabrication is a source of error. However, the manufacturing variation in dimension for a chosen magnet is usually relatively small, so the impact can be unsubstantial. However, making the intended size of the magnet diameter smaller, creates more pronounced errors for large system assembly tolerances.

In Figure 2-22 and Figure 2-23, the larger diameter magnet exhibits greater immunity to the sensor being offset from the ideal location centered right beneath the axis of rotation for the magnet. The 6-mm diameter magnet exhibits the greatest error, more than 2x what is observed for the 12.7-mm diameter. Worst case error for the side-by-side die is nearly double that of the stacked die.