SU1538046A1 - Method of measuring roughness of surface - Google Patents

Abstract

The invention is intended to measure surface roughness. The goal is to improve the measurement accuracy by determining the orientation of the micro-sites. The orientation of the microplots of the surface is determined from the intensity distribution of the reflected light flux by the position of the maxima in the intensity distribution, which is taken into account when determining the angles of inclination of the microplots, which characterize the surface quality. 2 Il.

Description

The invention relates to a measurement technique and is intended to control the quality of surfaces.

The purpose of the invention is to improve the measurement accuracy by determining the orientation of the micro-sites.

FIG. 1 shows a diagram of the device that implements the method; Fig. 2 is an axonometric projection of the micro-site under study and the course of the rays.

The device contains a white light source 1, aperture 2, micro-lens 3, fiber optic cable C, in which one of the central light-guides 5, located by the input end at the focus of micro-lens 3, light-fibers 6, multiplied system 7, containing an array of photodetectors 8 and analog digital converter (ADC).

The method is carried out as follows.

The radiation of the source 1 is directed perpendicularly (OA in Fig. 2) to the local section 10 of the surface 11 under study through one of the central fibers of the tow 4 coinciding with the input section with the center of the polar coordinate system 0. The intensity distribution of the light reflected by the surface is recorded in the plane of the input section tow 4 and highlight the pattern of intensity distribution. Its polar coordinates (g, iЈ) are associated with the coordinates of the corresponding receiving fiber AB (Fig. 2), which shows the path of the beam transmitting the reflected light of maximum intensity. In Figure 2, H is the distance from the surface to the entrance section of the optical fiber bundle 4.

The tilt angle of the microsite cЈ (FIG. 2) is determined by the formula

- tarctg

(/

ate

oz oo

about

4i

ABOUT

The angle of rotation of the microsite relative to the incident beam (Fig. 2) is found through the polar angle if: 8 T-ip.

Thus, the measurement of the entire range of angles of rotation is taken, and the range of measured angles of inclination is determined by the condition for detecting the reflected beam.

D

1-arctgf- M arctg,

where d is the diameter of the light bundle,

D is the diameter of the fiber-optic

harness

By decreasing H and increasing D, it is possible to extend the range of maximum measured values of tilt angles

 Up to 45 °

.

Thus, due to the determination of the orientation of the micro-site from the angle of inclination and angle of rotation, the accuracy of determining the quality of the surface as a whole is improved.

five

0

Claims (1)

Invention Formula The method of measuring the surface roughness, consisting in that the luminous flux is directed to the local surface area, determines the intensity of the luminous flux reflected from the surface in a plane parallel to the surface plane, calculate the angles of inclination of the microparts, which determine the roughness surface, characterized in that, in order to increase the measurement accuracy by determining the orientation of the microplots, after determining the intensity, the coordinates of the maximum intensity distribution are determined, and the microslope tilt angles are calculated from the coordinates of the maximum of the intensity distribution of the reflected light flux; the microsites are determined with respect to which the roughness is judged. YU iL AT - # FIG L FIG. 2 I