DEVICE FOR MEASURING AMPLITUDES OF SMALL PERIODIC LINEAR DISPLACEMENTS Russian patent published in 1995 - IPC

FIELD: measurement technology. SUBSTANCE: device has reference laser 1 with active element 2, absorption cell 3, mirrors 4 and 5 mounted on piezocorrectors 6 and 7, light splitter 8 and light connector 9, photodetectors 10 and 11. The reference laser is optically coupled through light splitter 8 and light connector 9 with photodetectors 10 and 11. The device furthermore has laser-sensor 12 one mirror 3 of which is attached to moving object 14. Laser-sensor 12 is optically coupled with one of the inputs of synchronous detector 16 the output of which is connected to one of the inputs of adder 17. Reference voltage generator 18 is connected to the second input of synchronous detector and through a first switchable circuit of electronic switch 19 is connected to piezocorrector 6. Saw-tooth voltage generator 20 is connected to piezocorrector 7 and to the start-up input of frequency meter 21 and control input of electronic switch 19. Photodetector 11 through DC amplifier 22 and peak detector 23 is connected to the second switchable input of electronic switch 19. The second switchable output of electronic switch 19 is connected to the second input of adder 17 the output of which 19 is connected to the second input of frequency meter 21. Such arrangement permits to measure a time interval corresponding to laser-sensor frequency deviation value and respectively to an object oscillation amplitude , and a time interval corresponding to frequency difference of two peaks of saturated absorption at the same values of sawtooth voltage and length of the second piezocorrector. EFFECT: enhanced measurement accuracy. 1 dwg