SU100446A2 - Optical visual pyrometer operating by the zonal (blue-red) ratio method - Google Patents

Description

BASIC Auth. St. No. 55713 describes a fluorescent wedge pyrometer with a screen located in the focal plane of the ocular and consisting of two halves, one of which is frosted glass and the other is a fluorescent substance. When a green light filter is placed in front of the ocular, and between the screen and the wedge of the second light filter, which transmits only violet and ultraviolet rays, a comparison is made of the fluorescence brightness caused by the ultraviolet or violet rays with the intensity of the green rays emitted by the glowing body.

The disadvantage of this pyrometer is that it is based on a comparison of the zonal spectral illuminations created by the radiating body, which makes it impossible to directly sight a red-hot object in the pyrometer and select a sufficiently small pyrometric area on its surface.

The basis of the described pyrometer in contrast to the pyrometer auth. St. No. 55713 a comparison is made of the spectral frequencies of the hot object, carried out by directly sighting in the okle a picture of this object and the pyrometering area located on its surface.

The peculiarity of the proposed pyrometer is that the fluorescent substance deposited on the opaque glass plane is located on the optical axis of the pyrometer. On this axis there is also a short-wave (for example, blue) light filter that overlaps the particle of the constant aperture of the object. the rest of which is obscured by the shortwave

a filter with a long-wave (for example, red) light filter with an adjustable light attenuator, connection :; with a pyrometer scale,

Figs 1 and 2 depict optical circuits of two embodiments of the proposed pyrometer.

Nirometer, rolled “and FIG. 1, is a telescopic system, in the back focal plane of the lens / which is placed frosted glass 2. A small portion in the center of the glass (in the form of a circle, square, etc.) is covered with a translucent layer of fluorescent substance 3 and thin (for example, film) a short-wave (“asarimer, blue) light filter 4. Part of the aperture of a fixed constant aperture 5, bounding the aperture angle of the lens, is blocked by a long-wave (6, for example, red) light filter 6, and the rest of this hole is blocked by otkovolnovym (e.g., blue) light filter 7 with the same spectral region of transmission as part filter 4. The apertures overlain longwave filter 6, light introduced adjustable attenuator 8 toto or other type KOTOpoiro position determined by the scale reading of pyrometer. For example, a red light filter 6 may have the form of a flat ring located around the circumference of the diaphragm, and the iris light 8 may serve as a light attenuator 8.

The observer sees in the eye 9 through a long-wave (red) filter 10 an image of the object to be liquefied on frosted glass 2. At the same time, the brightness of the center of the photo (luminescence) of this image is determined by the radiation energy in the short-wave (blue) part of the spectrum, and the brightness the rest of the image is the radiation energy in the long-wave (red) part of the spectrum.

The filters are selected so that the spectral transmission curves of the long-wavelength and short-wavelength light filters do not overlap.

The light attenuator 8 adjusts the brightness of the surrounding (long wavelength) image on frosted glass 2 at the same brightness of the peptralus (luminescent) area excited by short wavelength filtered light. Counting on the scale is taken when the photometric equality of the central spot with the rest of the image is achieved.

To extend the pyrometer scale towards higher temperatures, the design may be

A light filter is introduced in the path of light, before the image, with a greater transmission in the long-wave part of the spectrum than in the short-wave (for example, yellow glass). To expand the scale to lower temperatures, a light filter with a higher transmission in the shortwave part of the spectrum than in the longwave (e.g., blue glass) can be introduced.

FIG. 2 shows a basic optical scheme of a variant of the described pyrometer, characterized in that there is no long-wavelength (red) light filter in the plane of the aperture diaphragm 5 of the lens and that the light attenuator is adjustable li. The short-wave (blue) filter 7 is made movable so that it is introduced into the plane of the diaphragm 5, overlapping the tubes ;; o or a smaller part of its area, and the position of the filter 7 is related to the reading on the pyrometer scale.

As the light filter 7 is inserted, the lens is diaphragmed for long-eye (e.g., red) rays and a corresponding weakening of the brightness of the surrounding comparison field in the ocular 9, with a significantly smaller attenuation of short-wave (e.g., blue) rays and a dependent central intensity of the comparison field ( fluorescent substance 3}.

By changing the profile of the contour of the movable light filter 7, any dependence can be obtained for the construction of a pyrometer.

Subject invention

1. Optical visual pyrometer operating according to the zonal (blue-red) ratio method, using a fluorescent substance introduced into one of its light paths, according to the author. St. No. 55713, characterized in that, in order to compare the zonal spectral icalities of a hot object by directly sighting in the ocular of a reproduction of this object and located on its surface with a feast