Dimensional measurement of internal profile using the optical caliper

Dimensional measurement of internal profile is conventionally performed mechanically with instruments like vernier calipers. Here, we cope with the measurement by using an optical caliper. The caliper consists of a semiconductor laser, a right conical mirror, a lens system, and an image sensor. The concept of the measurement approach is intersecting the object with a disk light sheet, collecting the cross-sectional profile image with an image sensor, and extracting dimensions of the profile. Example of practical measurement is presented.