The distance between adjacent measurement points along a scan line, in centimeters. Smaller spacing captures more detail where the field changes quickly (near coil edges or wire path). Larger spacing works fine for slowly varying interior regions. Recommended starting values: 1 cm for discs and pancakes, 2.5 cm for loops, 1.5 to 2.5 cm for rectangular mats. Adjust based on accessory size to keep about 8 to 12 points per half-axis.
The field is measured on a grid. Starting at the center, the test engineer steps a probe outward along each axis at a fixed point spacing, taking a reading at every point, and continues a little past the accessory edge to catch the field as it fades. The origin is the center of the accessory surface.
