SU1442826A1 - Photometric method of measuring linear dimensions - Google Patents

Abstract

The invention makes it possible to measure the linear size of the object and the taper of the outer conic parts. The aim of the invention is to increase the information content by measuring the angle of the outer cone. The collimated beam of light is directed at the cone, the beam is partially shielded by it, the beam with the mobile profile in cross section is extracted from the unshielded part of the beam, mixed, spun it at a constant, linear velocity normal to the axis of the controlled cone, measured the time of change of the photosignal when it overlaps with the controlled cone, and the angle of the controlled cone is calculated from the value of the speed of displacement and its geometrical parameters. 2 Il.

Description

1HE

00 GcE

O5

The invention relates to a measurement technique and can be used for non-contact measurement of the linear dimensions of objects and the taper of external conical parts.

The purpose of the invention is to increase the information content by measuring also the angle of the outer cone.

FIG. 1 is a schematic diagram of the measurement; in fig. 2 shows the profile of the ejected part of the beam relative to the generatrix of the controlled conical part.

The measurement scheme (Fig. 1) contains a source of light 1, forming a collimated beam, w, a spruce diaphragm 2 fixedly mounted, an unwrapped cylinder 3, on the side surface of which an opaque coating is applied, in which a shelel diaphragm - slot is made 4 in the form of a helical strip in one turn, a photodetector 5 installed at one of the ends of the development cylinder 3, a differentiating amplifier 6, a processing unit 7 determining the time of change of the photosignal, and a mechanism 8 of uniform rotation of the development cylinder and 3 with a rotation speed sensor (not shown). Controlled cone 9 is characterized by half of its angle. The size from the beginning of the overlap of the generatrix of the cone of the extracted part of the radiation beam to its end is equal to Vt. The profile 10 of the emitted portion of the radiation beam (Fig. 2) has an angle jf and the dimensions of the emitted portion of the beam are defined as a and v.

The measurements are carried out as follows.

A collimated beam is directed from the light source 1 to a controlled cone 9. From a part of the beam that is not shielded by a slit diaphragm 2 and a slit 4 in a development cylinder 3, a part of the beam with a rhombic profile 10 is cut in its cross section (Fig. 2). . The selected part of the beam, penetrated inside the development cylinder 3, is received by the photodetector 5. With a uniform rotation of the development cylinder 3, the output part of the beam moves with a constant linear velocity (V) along the slit diaphragm 2. As a result, the output part of the beam moves relative to the generator of the controlled cone 9 at the exit photodetector changes photo signal. A change in the photo signal is determined by differentiating amplifier 6. The change in the photo signal starts at the moment of overlapping of the selected part 10 of the collimating beam of the generator of the monitored cone 9, and this change continues until you completely overlap

the divided part of the radiation beam controlled by the cone. The photo signal from the photodetector 5 and the amplifier 6 is fed to a processing unit that determines the change time (t) of this signal.

Based on the measured values of the speed of movement (V) of the selected part of the radiation beam and its linear dimensions, the profile of the selected part of the beam is determined preliminarily taking into account the parameters of the slit diaphragm and the slit slot in the developable cylinder, calculate the angle of the controlled cone from

15

2t, j /

2tgr-2 in / a,

0

five

0

five

0

five

WhereU, S - screw pin, slotted slot in the development cylinder;

and) the rotation speed of the development cylinder.

Claims (1)

Invention Formula The photometric method of measuring linear dimensions, which consists in forming a collimated beam of light, extracts from it a part of the beam with a rhombic profile using fixed and movable slit diaphragms, the slit of one of which is made linear, the other along a helical line, guide the selected part of the beam to the object, evenly move the selected part of the beam relative to the object being monitored, determine the speed of movement of the selected beam, take the unshielded part of the light beam and convert it A photo signal, judging by the value of a controlled parameter, characterized in that, in order to increase the information content by measuring also the angle of the outer cone, the cross section profile of the selected part of the beam is preliminarily measured, the movement of the selected part of the beam is carried out in the direction perpendicular to the axis of the controlled cone, simultaneously with its displacement, measure the time of change of the photosignal and calculate the angle of the cone according to 2tg -2tgf -2v / a, where is the half angle of the external cone; V is the speed of movement of the selected beam parts; j is the acute angle of the transformed beam profile; O-iS - width and profile length of the transformed beam; t is the time of signal change. X . . FIG. one G1 atgoi -atgr