SU896397A1 - Device for measuring deformation rate - Google Patents

Description

(54) DEVICE FOR MEASURING SPEED

DEFORMATION

one

The invention relates to a measurement technique, and more specifically to the field of measuring the rate of ceformation by optical methods.

A device for measuring strain rate is known, which contains a coherent radiation source, a Fabry-Perot interferometer, and a Doppler frequency registration circuit 1.1.

The disadvantage of such a device is the necessity of recalculating the velocity vector to the corresponding coordinate axes, which complicates the measurement scheme.

The closest to the technical essence of the invention is a device for measuring the strain rate, containing a coherent radiation source and installed a translucent mirror along the light beam, an optical heterodyne photodetector and a measuring circuit 23.

The disadvantage of such a device is the presence of two base points in the measurement

deformations, which reduces the accuracy of measurements,

The purpose of the invention is to improve the accuracy of measuring the strain rate. This goal is achieved by the fact that the device is equipped with an optical delay line of the reflected beam, made in the form of two beam splitters and a return prism between them, set along

Jjj go light beam pepper photodetector.

The drawing shows the optical layout of the device.

Speed measuring device

J5 deformations contains a source of coherent radiation 1 and a translucent mirror 2 installed along the light beam, an optical heterodyne photodetector 3, a measuring circuit 4,

Claims (2)

2Q is an optical delay line of the reflected beam, made in the form of two light headers 5 and 6 and a return prism 7 between them, mounted along the light beam by a pepper by a photoreceiver 3. The device operates as follows. The light beam from the source 1 coho envolves N: the radiation passes through the semi-transparent mirror 2 and hits object 8, the reflected radiation, with the help of the semi-transparent mirror 2, is directed to the beam splitter 5, where the beam is divided into two parts, one of which is directed to the photodetector 3, and a friend to the optical delay line, consisting of the beam splitter 5, the return prism 7 and the beam splitter 6. After the delay line passes, both beams are folded on the photo receiver 3, where the Doppler frequency is allocated, which is then recorded by the meter Scheme 4. The motion of an object 8 (e.g., a cylindrical shell) under the action of a magnetic pulse generator 9 changes the frequency of the reflected beam and results in an output signal proportional to the speed of the object's motion. The application of the present invention improves the measurement accuracy, since the measurements are carried out practically at a point whose dimensions are determined only by the beam diameter, in addition, the use of a delay line reduces the difference frequency at the photocapsule, which increases the stability of the device -keeping. An apparatus for measuring the strain rate, comprising a coherent radiation source and a translucent mirror installed according to a light beam code, an optical heterodyne photodetector and a measuring circuit, characterized in that it is provided with an optical delay line of the reflected beam made in the form of two beam splitters and a reverse prism between them, installed along the light beam in front of the photoreceiver. Sources of information taken into account in the examination 1. Vasilenko Yu. G. and others. Laser Doppler velocity meters. Science 1975, p. 12. 2. USSR author's certificate 545856, cl. G 01 B 11/16, 1975.