Castroviejo Caliper, 7 cm – 20 mm Measuring Range

Measuring range matters more than overall length on a caliper, and 20 mm is deliberately small. A scale covering only the distances actually being measured can space its graduations further apart, so each division is easier to read and the reading is less prone to error. A caliper with twice the range fits twice the scale into the same space, and every graduation is correspondingly finer.

That suits ophthalmic and microsurgical work, where almost nothing being measured exceeds 20 mm and the measurement is often read under magnification. The 7 cm body sits entirely within the hand, so the instrument is steadied by the fingers rather than balanced. Smooth action is the other requirement — a caliper that sticks or jumps gives a reading that reflects the mechanism rather than the tissue.

Specifications