Multi-Finger Caliper tools provide direct, precise and reliable measurements of internal tubing and casing diameters. The applications include the evaluation of corrosion, erosion, wear, bending, buckling, pits, holes and other defects with high accuracy in both drilling and production. Measuring fingers move radially along the inner casing or tubing wall, detecting any diameter change. This generates a high-resolution record of the tubular geometry which can be observed and presented as a conventional log, a cross section, or a 3-D color enhanced image.