PURPOSE: To measure tools precisely by detecting the values of the edge point of tools as functions of distance from crisscross coordinate axes and applying impulses for distance value compensation to a servomotor till the tools are placed into a new tool position where they show no X-axis and Z-axis deviation.

CONSTITUTION: The optical system of a carriage 3 includes a camera 7 connected to an image processing computer 9 and provided with calculated planar array stored in the computer 9. The carriage 3 has a servomotor 14 for orientation. The computer 9 detects the values of an edge point 21 of a tool 20 as functions of distance from crisscross coordinate axes and applies impulses for distance value compensation to the servomotor 14 accordingly to measure the tool 20 precisely. The computer 9 is also connected to another digital computer 6 that displays the measured coordinate values of the tool edge point 21.