Ideal Gas Thermometer and Temperature Measurement by Mechanical and Electrical Effects I — Lesson 1

This lesson covers the various methods of temperature measurement in fluid mechanics. It begins with a discussion on the ideal gas thermometer, explaining its use for measuring temperatures less than 1 degree Kelvin. The lesson then delves into the equation of state for an ideal gas and how it can be used to construct an ideal gas thermometer. The lesson also covers the concept of temperature measurement by mechanical effects, focusing on the use of bimetallic strips and liquid-in-glass thermometers. It explains how these devices work, their applications, and potential sources of error. The lesson concludes with a brief introduction to temperature measurement by electrical effects, which will be discussed in detail in the next lesson.

Video Highlights

02:12 - Equation of state for an ideal gas and its application in the ideal gas thermometer
04:14 - linear relationship between pressure and temperature in a sealed container of constant volume
07:24 - Calibration of ideal gas thermometer using a known temperature and pressure point
24:35 - Concept of temperature measurement by mechanical effects, focusing on thermometers based on thermal expansion of liquids and gases
35:07 - Different types of liquid in glass thermometers
46:08 - How bimetallic strips can be used to measure temperature, including the impact of different thermal expansion coefficients

Key Takeaways

- The ideal gas thermometer is used for measuring temperatures less than 1 degree Kelvin.
- The equation of state for an ideal gas can be used to construct an ideal gas thermometer.
- Bimetallic strips and liquid-in-glass thermometers are common devices used for temperature measurement by mechanical effects.
- These devices work based on the principle of thermal expansion and can be calibrated for accurate temperature measurement.
- The accuracy of these devices depends on the care with which they were constructed and calibrated.