Unit 8: Temperature Measurements Temperature control is fundamental to most chemical, biological, and mechanical processes. In order to determine which temperature sensor or transducer is appropriate for a given situation, you must consider a number of factors, including operating environment and desired temporal and measurement sensitivity. In this unit, you will review common temperature scales and the characteristics of commonly-used temperature measuring devices.
Unit 8 Time Advisory
This unit should take you 12 hours to complete.
☐ Subunit 8.1: 1 hour
☐ Subunit 8.2: 2 hours
☐ Subunit 8.3: 2 hours
☐ Subunit 8.4: 2 hours
☐ Subunit 8.5: 1 hour
☐ Subunit 8.6: 3 hours
☐ End of Unit Self-Assessment: 1 hour
Unit8 Learning Outcomes
Upon successful completion of this unit, the student will be able to:
- Demonstrate use of common temperature scales.
- Demonstrate knowledge of the relative merits of common instrumentation, including expansion thermometers, thermocouples, and thermistors.
- Experiment with the dynamics of a temperature sensor, analyze data, and formulate conclusions.
8.1 Temperature Scales
- Reading: NASA: Cryogenics and Fluids Branch of the Goddard Space
Flight Center’s “Temperature Scales and Absolute Zero”
Link: NASA: Cryogenics and Fluids Branch of the Goddard Space Flight
Center’s “Temperature Scales and Absolute
Instructions: Read the text and then calculate the following: room and body temperature in degrees Fahrenheit, Centigrade, Kelvin, and Rankine. What is the meaning of negative absolute temperature?
8.2 Expansion Thermometers Note: You are probably familiar with the liquid-in-glass expansion thermometer, although its use is declining with time. You may have encountered one in a chemistry laboratory, in cooking candy, or for a body temperature measurement. Another type of expansion thermometer makes use of the differential expansion of two metals and is hence called a bimetallic expansion thermometer. These have been used in devices like thermostats, in which some mechanical action is required as a function of temperature.
- Reading: University of California – Riverside: Beverly Lynds’
Link: University of California – Riverside: Beverly Lynds’ “About
Instructions: Read the linked section above. The discussion is wide-ranging, but is particularly useful for understanding the physics of liquid and gas expansion thermometers.