FIELD: measurement technology. SUBSTANCE: method involves taking measurements in forward and backward stroke of spindle. Before performing the backward movement, the spindle is rotated to the given angle of α about vertical axis that is defined as 
, where n is the number of measuring support members spaced over device working part perimeter. The device has hollow casing having at least one opening in lateral wall, strain-measuring beams with strain-gage resistors supported as cantilevers in the casing in front of each hole in its lateral wall, measuring support members mounted in lateral wall holes which one end is engageable with the surface under control and the second one makes permanent engagement with the corresponding strain-measuring beam, and members for fixing measuring support members designed as pressure beams fixable in the casing. The working part of the device is axially connected to hollow elongation rod, the opposite end of which has stem fixable in spindle mandrel of vertical boring machine. Each fixing member is manufactured from hard elastic material and fixed in the casing with constant radial detachment of the measuring support member towards the lateral wall of the casing. The elongation rod has hole in lateral wall before the stem for connecting wires to be conducted from strain gages to recording devices. EFFECT: high accuracy and reliability of measurements. 5 cl, 2 dwg
