An electrode for use in a welding process may comprise a finite length electrode core. The directional solvent is heated to dissolve water from the salt solution into the directional solvent. Each image sensor has an upright physical orientation corresponding to an upright orientation of the optical image and is capable of rotation about the rotational axis to orient the image sensor in the upright orientation. The sub-circuit netlist contains significantly fewer paths than the HDL netlist of an entire design so that its simulation time is much quicker. A second calibration feature can be printed at a second lateral location on the medium. A fiber optic probe is provided for examining large samples or samples at remote sites.