RU211394U1 - Stand for measuring the coefficients of diffuse and specular reflections - Google Patents

Abstract

This device belongs to the field of verification and measurement of optical parameters and is designed to measure the coefficients of diffuse and specular reflections from the inner surface of the cylinder. The objective of the utility model is to create a stand that provides an extension of the functionality for measuring the coefficients of diffuse and specular reflections for closed surfaces of the cylinder. The technical result that allows solving this problem is the placement of the emitter and (i+1) photodetectors on a matrix inside the cylinder. The stand for measuring the coefficients of diffuse and specular reflections contains an emitter with a radiation collimator and a rotary device, which are mounted on a guide with connecting wires connected to a matrix of photodetectors placed on a light-absorbing screen along the entire length of the cylinder, characterized in that the emitter and (i+1) photodetectors on the matrix are placed inside the cylinder, and the intensity of the beam from the reflection on each (i + 1) photodetector of the matrix is measured, and the coefficient of diffuse and specular reflections is measured for different angles of beam incidence on the mirror surface and for different parts of this surface. 2 w.p. f-ly.

Description

The utility model relates to the field of checking and measuring optical parameters and is designed to measure the coefficients of diffuse and specular reflections from the inner surface of a cylinder. This device is based on the method of comparing the intensity of the beam from the emitter with the intensity of the beam reflected diffusely (Ai) on the photodetectors 6 or reflected specularly (A0) on the photodetector 9 in the center of the matrix. The presence of a matrix of photodetectors and the possibility of linear displacement of the emitter relative to the matrix makes it possible to achieve high accuracy of the result. For the diffuse reflection coefficient, the result is obtained by integrating over the entire surface of the cylinder, taking into account the measurement results Ai, obtained on i photodetectors 6. The result is obtained as a result after measurements at different angles of incidence of the beam from the emitter and after scanning the surface of the cylinder, followed by finding the average value over all these measurements .

A known method for measuring the reflectance of mirrors (see patent No. RU 2665594 C1). The method consists in measuring the intensity of the incident (A) and reflected (A1) beams of radiation using a receiver rotated around an axis passing through the center of the area of the measured mirror surface and perpendicular to the plane of incidence, followed by calculation of the reflection coefficient.

The disadvantages of the prototype are:

the impossibility of taking measurements for the inner surface of the cylinder, only for open convex or concave surfaces;

only the specular reflection coefficient is measured.

The proposed device solves the problem - the creation of a stand that provides an extension of functionality for measuring the coefficients of diffuse and specular reflection for closed surfaces of the cylinder.

The technical result obtained in the implementation of the utility model is to place the emitter and (i+1) photodetectors on a matrix inside the cylinder. The intensity of the beam from reflection is measured at each photodetector of the matrix, and on one of them (A0) 9 we obtain the intensity of the specularly reflected beam, and on the remaining i photodetectors (Ai) 6 - the intensity of diffusely reflected beams. The maximum value of A0 on one of the photodetectors at a given intensity of the emitter is achieved by fine tuning the linear shift of the emitter relative to the array of photodetectors. The intensity distribution on the remaining i photodetectors (Ai) is compared with the calculated values, from which the diffuse and specular reflection coefficients are found. To achieve high accuracy, each photodetector is calibrated before measurements using a coupling in direct radiation to the photodetector according to a given intensity of the emitter.

The essence of the utility model is illustrated by the drawing.

In FIG. 1 shows a diagram of a stand for measuring the coefficients of diffuse and specular reflections, where:

1. Emitter

2. Collimator

3. Rotary device

4. Guide

5. Connecting wires

6. Matrix photodetectors

7. Light absorbing screen

8. Mirror surface of the cylinder

9. Central photodetector for reflected specular beam

The device works as follows.

Before starting work, it is necessary to calibrate the stand, for which it is necessary to remove the emitter and, using a coupling, connect the emitter in turn to each photodetector to receive direct radiation and, turning on the power to the emitter, record the readings of each of (i + 1) photodetectors when receiving direct radiation from emitter. These readings will make it possible to normalize the signal for each photodetector and will be used to further calculate the coefficients of diffuse and specular reflection from the inner surface of the cylinder according to the measurement readings on (i + 1) photodetectors. At the end of calibration, it is necessary to disconnect the emitter from the photodetector and install it in the socket of the rotary device on the guide. Next, insert the guide with the emitter and the matrix of photodetectors inside the cylinder and fix their position with a light-absorbing screen inside the cylinder. Set the angle of the emitter, connect the collimator and turn on the supply voltage to the emitter and photodetectors. Measure the current on photodetector #09 in the center of the matrix and fine-tune the emitter to the position for which the current of photodetector #0 is maximum. Comparison of the value of this current with the value obtained by calibrating the instrument determines the mirror reflection coefficient. Further, by switching the channel number, we sequentially measure the currents from the 1st to the i-th photodetector. These i values of currents are compared with the calculated values for given diffuse and specular reflection coefficients, and the model that best agrees with the measured data is taken as the desired one. This procedure is repeated for different angles of beam incidence on the surface of the mirror surface and for different parts of this surface by simply turning the emitter, as well as moving the ruler and rotating the cylinder around its axis. The final result is found by averaging all the obtained values.

Thus, the use of this technical solution significantly expands the functionality of the stand for measuring the coefficients of diffuse and specular reflections. The inventive stand can be widely used in industry for measuring optical parameters.

Technical solutions with features that distinguish the claimed solution from the prototype are not known from the prior art. This allows us to consider that the proposed solution is new.

Claims (3)

1. Stand for measuring the coefficients of diffuse and specular reflections, including the emitter 1 with a radiation collimator 2 and a rotary device 3, mounted on a rail 4 with connecting wires 5 connected to a matrix of photodetectors 6, 9, placed on a light-absorbing screen 7 along the entire length of the cylinder 8 , characterized in that the emitter and (i+1) photodetectors on the matrix are placed inside the cylinder. 2. Stand for measuring the coefficients of diffuse and specular reflections according to claim 1, characterized in that the beam intensity is measured from reflection at each (i + 1) photodetector of the matrix. 3. Stand for measuring the coefficients of diffuse and specular reflections according to claim 1, characterized in that the coefficient of diffuse and specular reflections is measured for different angles of beam incidence on the mirror surface and for different parts of this surface.

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