FIELD: measurement technology, specifically, measurement of deviations of key slots with reference to axes of through holes. SUBSTANCE: object to be measured is placed in case by putting it with hole on to centering fingers so that contact of measuring test prod of reading head with side surface of tested slot is ensured. Mutual angular positions of object to be measured and case are adjusted by way of reciprocating-rotary motions of object to be measured on centering fingers and by movement of slider in direction of depth of tested slot to achieve invariability of readings of reading head under mentioned movement of slider. First reading is taken. Object to be measured is put on centering fingers anew to ensure contact of measuring test prod with another side surface of tested slot. Mutual angular positions of object to be measured and case is adjusted again. Second reading is taken and desired-for deviation from symmetry is found by half-difference of difference. EFFECT: increased measurement precision thanks to enhanced reliability of basing of object to be measured on device. 2 dwg
