X-PLAN F series
This is the best digital planimeter. All of the functions provided with the former X-PLAN's C+ and CII+ are taken over by the F series as they were.
And it has newly added special measurements.

Measuring Functions

Area / Length(total/segment) / Coordinates
Radius / Centroid / Triangular Area(base/height/area)
Angle / Center of Circle / Radial Distance
Contour-based Volume / Affine Transformation
Revolutionary Solid(volume/surface area/center of gravity)
Point Marking