Temperature Measurement by Radiation and the Optical Pyrometer — Lesson 4

This lesson covers the principles and techniques of measuring temperature using an optical pyrometer in the field of Fluid Mechanics. It delves into the concept of radiative heat transfer and how it can be utilized to measure temperature. The lesson explains the function of different components of an optical pyrometer, such as the front lens, absorption filter, standard lamp, red filter, and eyepiece. It also highlights the advantages of this method, such as its non-invasive nature, and its limitations, such as the requirement for the object to produce visible light. An example of plotting the distribution of thermal radiation energy for different temperatures is also discussed.

Video Highlights

00:41 - Principle of measuring temperature using optical pyrometer
02:12 - Measurement of temperature using thermal radiation
06:31 - Planck's distribution law
17:59 - Wien's law
24:27 - Optical pyrometer and its components
38:55 - Calibration of the current to the lamp and slide wire position in temperature

Key Takeaways

- An optical pyrometer uses the principle of radiative heat transfer to measure temperature.
- The method is non-invasive, requiring no direct physical contact with the point where the temperature is being measured.
- The optical pyrometer consists of several components including a front lens, absorption filter, standard lamp, red filter, and eyepiece, each serving a specific function.
- One of the limitations of this method is that the object or point whose temperature is being measured should produce visible light.