SU711382A1 - Temperature measuring device - Google Patents

Description

The invention is related to thermometry, and can be used to continuously study the temperature fields of various objects. Temperature measuring devices are known that contain a light source and a sensing element, the refractive index of which depends on temperature d. However, these devices have low measurement accuracy when using them to record thermal fields. The closest in technical terms to the proposed is a device containing a white light source, a capacitor and a sensing element made in the form of a cell filled with an optically inhomogeneous mixture of components with similar refractive indices and different temperature coefficients of refractive indices 2 The disadvantage of this device is the low accuracy of the measurement of the temperature fields due to poor color contrast. The purpose of the invention is to improve the measurement accuracy. This is achieved in that a temperature measuring device containing a white light source, a condenser and a sensing element made in the form of a cuvette filled with an optically inhomogeneous mixture of components with similar refractive indices and different temperature coefficients of refractive indices are placed between the source white light and a condenser, aperture and a matte screen placed on one side of the beam splitter along the axis of the reflected beam of light coming from the sensitive element, and an additional condenser, two drums with a set of neutral and bandpass filters and a mirror screen placed on the other side of the beam splitter, with the upper wall of the cell tilted to the base.

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The drawing shows a diagram of the proposed usgroysva.

The device comprises a white light source 1, for example, an incandescent bulb, a diaphragm 2 limiting the luminous flux, and a condenser lens 3 providing a parallel white light beam 4 directed perpendicular to the sensing element.

A light splitter 5 is installed between the source of light 1 and lens 3. It can be made in the form of a beam-splitting cube, obtained on the basis of two rectangular prisms, folded by oblique faces, on which a translucent mirror 6 is applied, partially transmitting and reflecting light incident on it. The sensing element is mounted on object 7, the temperature field of which is being investigated. Object 7 is opaque to white light, so the sensitive element can only work in reflected light. The sensing element is made on the basis of a cuvette 8 with a transparent top with a bag, for example made from glass. A specularly reflecting coating 9 is applied to the bottom wall of the cuvette 8. The cuvette 8 is filled with an optically inhomogeneous mixture of two components 10 and 11, for example, a liquid and optical glass powder, or a polymer and a powder (glass) powder. The components of the mixture are selected from the condition that their refractive indices are close in the operating temperature range of the element and the difference in temperature coefficients of the refractive indices. This provides optically: for a heterogeneous system, spectral selectivity and the ability to shift the bandwidth in accordance with temperature changes. The transparent upper wall of the cuvette 8 is made inclined with respect to the opposite wall with a specularly reflective coating 9. This allows to separate the light transmitted through the measuring element (rays 12) whose spectral composition carries information about the temperature of the object from white light reflected from the outer surface of the sensitive an item. The latter creates additional illumination and makes it difficult to analyze the spectral composition of the rays 12. The focus of the lens 3 for the beam of light 12, which unobstructedly passed through the sensing element, reflected from the mirror coating 9 and the translucent mirror 6 of the splitter 5, aperture 13 is installed.

The shape of the diaphragm 13 coincides with the image of the filament body of the source of white light. The maximum contrast is achieved.

visually observable color picture of the temperature floor. Behind the diaphragm 13 is a matte screen 14. For the same. axes, but on the opposite side of the beam splitter 5, a condenser lens 13 is positioned so that for a bunch of white light reflected from a translucent mirror 6 in the direction perpendicular to the main light flux, source 1 is in the focus of the lens 13. Over

lens 13 is a set of neutral filters 14 with different transmittance. Behind it is a set of bandpass filters 15 for the visible region of the spectrum. Light filters 14

and 15 are installed in the drums 16. By turning the drum 16 about an axis, any desired combination of neutral and band-pass light filters is obtained. For a set of bandpass filters 15 is a screen 17 with a specularly reflective coating. Suppose that it is necessary to determine the isotherms corresponding to light with a wavelength of D and Xg. located side by spectral scale,

for example, the red isotherm and orange. This can be done by setting alternately narrow-band light filters with wavelengths и и LL to obtain high contrast in the light beam 12.

the image of isotherms requires the use of filters with a very narrow bandwidth, which is difficult in the long wavelength region of the spectrum, and also leads to a reduction in the brightness of the observed isotherm. The task can be solved as follows. We introduce into the light flux, which gives images of a color pattern on the screen 14, additional light of a certain spectral composition, which in combination D and D 2 gives sharply contrasting colors. For example, blue and red give a dark brown-brown color, and blue and orange give a greenish brown. The introduction of additional blue simplifies the separation of isotherms red and orange.

Light of the desired spectral composition is selected using a set of neutral 14 and 15 bandpass filters. For this, part of the white light reflected by the semitransparent mirror 6 is collected with the help of a lens 13 and passed through the selected light filters 14 and 15. Pos

Claims (2)

Claim 1. A device for measuring temperature, containing a white light source, a condenser and a sensing element made in the form of a cuvette filled with an optically heterogeneous mixture of components with close refractive indices and different temperature coefficients of refractive indices, oh and 5 heme, which , in order to improve the accuracy of measurements, a beam splitter installed between a white light source and a condenser, a diaphragm and a matte screen placed 10 on one side of the beam splitter along the axis beam of light coming from the sensing element, and an additional condenser, as well as two drums with neutral and band-pass filter ¹⁵ frames and a mirror screen located on the other side of the beam splitter. 2. The device according to π. 1, distinguishing with heme, that the upper wall of Kyu ^{20 of the} Veta is inclined to the base.