METHOD OF MEASURING DIAMETERS OF HOLES USING MICROMETRE Russian patent published in 2012 - IPC G01B5/12 

FIELD: physics.

SUBSTANCE: method employs an additional device to the micrometre, which is fitted into the measured hole. The device has two diametrically lying inserts which are held apart by springs. Before measurement, the device is fitted into the measured hole. Under the action of two springs, the inserts come into contact with the surface of the hole through their outer surfaces, wherein the top ends of the inserts protrude from the end of the hole such that the heels of the micrometre can be placed against the outer surfaces of the inserts during the measurement process. Forces created by the springs must be such that surface roughness protrusions of the hole are not crushed on one hand and on the other, the force must be greater than the force created by the slack adjuster of the micrometre during the measurement process. After fitting the device into the hole, distance between the spring-loaded surfaces of the inserts is measured using an ordinary micrometre, and its readings are taken as the diameter of the measured hole. Roughness of the contact surfaces of the inserts and the surface of the hole must be equal and the material of the hole and the inserts must have the same hardness.

EFFECT: broader functional capabilities of a micrometre owing to the possibility of measuring the diameter of holes without other apparatus meant for measuring diameters of holes, owing to higher efficiency, accuracy and stability of measurement results.

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