Use of a system comprising an He–Ne laser and a position-sensitive photodiode in recording of angular displacements

A method was developed for measuring the instantaneous value of the azimuthal (angular) displacement of an impact of vibration bench under laboratory conditions. The main parts of the apparatus were an He–Ne laser (λ = 0.63 μ) and a detector with an FD-19KK silicon position-sensitive photodiode. The error in the determination of the angle of rotation under dynamic conditions depended on the nature of the laser and was 2–5''. The range of angles that could be measured was 0–10'. The pass band of the apparatus was 0–5 MHz.