After the initial design comes the final crucial steps of prototyping, testing, and revising. As the tool approximates the B-field based on ideal conditions, try to compensate with all sources that can be identified at the time of the preliminary design. In the course of building the prototype, there may be undesirable aspects of how the switch moves, additionally, various error sources that were not initially accounted for may be discovered. These various issues become more obvious with a physical prototype. Figure 2-18 is the prototype that was designed for this application report.