FIELD: measurement technology.
SUBSTANCE: method of measuring displacements consists in formation on surface of quadrant photodetector two light fluxes, conversion of optical signals into electrical and determining coordinates of optical signals from electrical signals. Two additional light fluxes at interfaces of adjacent quadrants of photodetector and modulate orthogonal functions. Signals are separated from each light flux with each quadrant. Formed from selected signals difference signals proportional to difference of electric signals from each light flux from each pair of adjacent quadrants. From difference between difference signals of each pair of opposite adjacent quadrants is determined on movement, and from sum of all difference signals is determined on angle of twisting.
EFFECT: simple method and high measurement accuracy.