CS242166B1 - Thermodynamic temperature measuring method - Google Patents

Description

The invention relates to a method of measuring the thermodynamic temperature of a thermal radiator. The method makes it possible to determine the thermodynamic temperature by the spectrophotometric method, taking advantage of the independence of the ratio Y; (l) from the values of unknown quantities existing in this measurement, such as the spectral sensitivity of the optical radiation detector s (Aj) spectral transmittance τ (Α) ) of the spectrophotometric apparatus used and the spectral emissivity ε (λ, Τ) of the investigated heat emitter.

The previously known measurement methods allow the determination of the spectral composition temperature or the total (radiation) temperature. In both cases, the accuracy and accuracy of the temperature determination is influenced by the emissivity properties of the investigated heat emitter. Measuring the emissivity of a thermal emitter is technically a very demanding process.

Furthermore, a method of determining the chromaticity temperature is known, which is based on measuring the spectral characteristic of the radiation intensity of the investigated heat emitter. From there, the chromaticity value is determined by calculation via trichromatic elements. The measurement of the spectral characteristics of the radiation intensity is done in a technically demanding manner. Determination of spectral characteristics The intensity of the radiation is influenced by the properties of the spectrophotometric apparatus used. The most important parameter that affects the accuracy and accuracy of the determination of the chromaticity temperature in the present case is the factor of the spectral transmittance of the apparatus used and the spectral emissivity of the investigated heat emitter.

Finally, a known method of measuring temperature by monochromatic pyrometry, which allows the thermodynamic temperature of a black or gray radiator to be determined but does not allow the determination of the thermodynamic temperature of a temperature radiator with a spectrally dependent emissivity characteristic of the investigated radiator. The temperature determined in this manner is, in the case of a temperature emitter having a spectrally dependent emissivity characteristic, in fact only the luminance temperature.

A suitable method for determining the thermodynamic temperature of the investigated heat emitter is not known.

The thermodynamic temperature measurement method according to the invention removes all the shortcomings of the hitherto known temperature measurement method, making it possible to determine the thermodynamic temperature of the heat emitter with sufficient accuracy and accuracy without requiring measurement of the spectral emissivity of the investigated heat emitter, spectral transmittance as well as without measuring the spectral dependence of the sensitivity of the optical radiation detector used, which does not allow any of the hitherto known methods of measurement, in that the thermodynamic temperature measurement method utilizes spectrophotometric measurements of the spectral characteristics of the emitted intensity of the investigated thermal radiator measured by a selective optical spectral response which is characterized in that the measured value signal V (A _S, T) proportional to the spectral intensity of radiation at a wavelength _the 1'ubovoine selected which lies to one side of the sharp local extreme použitéha spectral response of a selective detector of optical radiation is then tested at successive signals at (A j, T) which is proportional to the spectral intensity of the radiation at each wavelength and _f, which they are located on the other side of the sharp local extreme spectral sensitivity of the selective optical radiation detector and from the measured signals V (A _S , T) and V (Aj, T) the thermodynamic temperature T of the investigated heat emitter is determined by the iteration method.

[YJlj - Yi (2).] ² - min, (1) where

Yi (1) =

V (A _s , Tj νμ, τ) (2) [exp C2 / A_t.T - 1]

C2 = 0.014 388 K.m.

(4)

Example:

The measured values of the signals are proportional to the spectral components of the radiation intensity of the investigated heat emitter. The signal values are measured as relative values. The signal measured on one side of the local extreme of the optical detector used shall be:

W [A _S, T) = 1.532, and was measured at a wavelength _of A - = 440 nm.

For the wavelengths I L lying on the other side of the extreme, the following signal values were measured:

I nm V (A _f , T) 5 584 585 8,747 8,599 6 582 8,919 583 8,828 586 8,481 587 8,359 From there' from condition (1) we get: A, nm 584 585 586 T _K condition results (1 j 2573 l, 5-8e 2.2E-8 l, 5-6e 2574 2.0E-5 3.8E-9 l, 4 e-5 2575 2.2E-5 7.8E-8 l, 5-3e

The thermodynamic temperature sought is thus

T = 2574 K.

By linking the investigated heat emitter to the temperature standards of the spectral composition, it was found that T _d = 2571 K. Thus, the difference between the calibration and this way determined temperature is

ΔΤ = 3 K.

The method of measuring the thermodynamic temperature of the heat emitter can be used in the primary etalon, both in photometry and in high temperature pyrometry, and wherever a precise determination of the temperature of the object to be considered as a continuous heat emitter is required. (Continuous in the present case means that it has a radiation characteristic of a spectral dependence of the intensity of radiation that can be expressed by a smooth continuous function).

Claims (4)

SUBJECT We claim: Method of measuring the thermodynamic temperature from spectrophotometric measurements of the spectral characteristic of the intensity of radiation of the investigated heat emitter using a selective optical radiation detector with sharp local extreme spectral sensitivity, characterized in that the selective optical radiation detector measures the spectral intensity signal V (A _S , T) wavelength A _of arbitrarily selected, which lies on the one hand from the sharp local extreme spectral sensitivity of the selective optical radiation detector used, then the values of the signals V (Aj, T) are measured successively in proportion to the spectral intensity values at each wavelength A, which are located on the other side of the sharp local extreme of the spectral sensitivity of the selective optical radiation and from the measured signals V (A _S , T) and V (Ai, T) the thermodynamic temperature is determined by the iterative method ota T of the investigated thermal radiator from the relation: (YJ1) - Yi (2j) 2 min, (1) where Yi (D In (A _S, T) V (A, T) A, ₅ _ [exp En / AJ.T - 1] A _s ' [exp C2 / A _S .T - 1] (2) C2 = 0.014 388 Kun. (4)