Аналітичний огляд методів та засобів вимірювання температури об’єктів малих розмірів

Abstract

Проаналізовано основні переваги та недоліки контактних та безконтактних методів і засобів вимірювання температури та можливість їх застосування для вимірювання температури мікро- та нанооб’єктів. Враховуючи результати виконаного аналізу, переваги та недоліки розглянутих методів, для вимірювання температури об’єктів малих розмірів оптимальним є застосування методу комбінаційного розсіювання світла. Показано доцільність використання методу за зсувом частоти комбінаційного розсіювання світла для побудови засобу вимірювання температури нанооб’єктів, що забезпечує зменшення часу вимірювання та методичної похибки.

The article reviews and analyzes the most common methods of measuring temperature. Also, the possibility of applying these methods to measuring the temperature of Nano objects has been studied. As a consequence, it is determined that the method of combining light scattering is best suited for solving such an engineering problem. Means of measuring the temperature based on the method of the combination of light scattering can be constructed according to the following dependencies:1. Dependence of temperature on the intensity ratio of the Stokes and anti-Stokes components of the spectrum of light scattering;2. the dependence of the shift of the frequency of the combination of light scatter from the temperature. Both methods have a methodological error in measuring the temperature which is associated with the heating of the object being studied by a laser beam. During the measurement, the temperature of the object being studied is constantly increasing due to the energy received from the laser. When using the first method, the Stokes, and then the anti-Stokes components of the spectrum of light scattering are first measured. The total measurement time can be up to 40 seconds. Therefore, the anti-Stokes component is measured at a different temperature of the test sample, which leads to a significant increase in the methodological error of measuring the temperature by the method of the combination of light scattering. In the second method, only the anti-Stokes component of the spectrum of the combination scattering of light is measured, which changes the temperature of the equivalent frequency of the spectrum of light scattering. The measuring time decreases at least twice as compared to the first method, the heating of the object under study by the laser beam decreases, which reduces the methodological error of measurement of the temperature by the method of the combination of light scattering. It is known that at temperatures of 300 ÷ 400 K the intensity of the anti-Stokes line is very small, therefore the method of thermometry in relation to Is / Ias is less convenient than the method of shifting the frequency of light scattering. From the measuring characteristics of the thermometry of the combination light scattering, the most important is the high spatial resolution, which is close to half the wavelength of the probe light. When ion or electron bombardment of the surface is possible generation of non-equilibrium photons. At the same time, the intensity of the anti-Stokes line of the combination light scattering may increase substantially, which is manifested in an abnormally low ratio of I / Ias for the given temperature. The problem of registering such states lies in the fact that in the collision of one particle with the surface, the inequality is localized in very small station-temporal intervals. (at the lengths of the order of 10-7 cm and the time 10-12 s), and when the averaging over the area of the probe beam and the time of sounding, the recorded effect can be extremely small.

Проанализированы основные преимущества и недостатки контактных и бесконтактных методов и средств измерения температуры и возможность их применения для измерения температуры микро- и нанообъектов. Учитывая результаты проведенного анализа, преимущества и недостатки рассмотренных методов, для измерения температуры объектов малых размеров оптимальным является применение метода комбинационного рассеяния света. Показана целесообразность использования метода по сдвигу частоты комбинационного рассеяния света для построения средства измерения температуры нанообъектов, что обеспечивает уменьшение времени измерения и методической погрешности.