An optimeter is a device for measuring linear dimensions (by the relative method), in which the lever-optical mechanism serves as a converting element. The lever gear of the optimeter is a swinging mirror in the mechanism, and the autocollimation tube is an optical converter.

Vertical optimeters and horizontal optimeters are designed to perform accurate linear measurements by the contact relative method.

On vertical optimeters mod. ИЗВ can measure end measures of length, the outer diameters of calibers and other products, the diameter of balls, wire, etc.

On horizontal optimeters mod. ИЗГ can be measured both external and internal dimensions.