Theory and Design for Mechanical Measurements
6th Edition
ISBN: 9781118881279
Author: Richard S. Figliola, Donald E. Beasley
Publisher: WILEY
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Chapter 8, Problem 8.33P
An iron-constantan thermocouple is placed in a moving air stream in a duct, as shown in Figure 8.48. The thermocouple reference junction is maintained at 212 °F. The wall temperature, Tw>is 500 °F, and the air velocity is 200 ft/s. The output voltage from the thermocouple is 14.143 mV.
Figure 8.48 Schematic diagram for Problems 8.33, 34, and 35.
- Determine the thermocouple junction temperature.
- By considering recovery and radiation errors, estimate the possible value for total error in the indicated temperature. Discuss whether this estimate of the measurement error is conservative and why, or why not. The heat-transfer coefficient may be taken as 70 Btu/hr-ff-°F.
| Air Properties | Thermocouple Properties |
| Cp = 0.24 Btu/lbm°F | r = 0.7 |
| U = 200 ft/s | e = 0.25 |
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Chapter 8 Solutions
Theory and Design for Mechanical Measurements
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