A thermocouple is used to measure the temperature of hot gas flowing in a duct having a wall temperature of 700 K. The temperature indicated by the thermocouple is 900 K. Estimate the true temperature of the air. Take the duct walls to be effectively "black", the emissivity of the thermocouple bead to be 0.2 and the convective heat-transfer coefficient between gas and thermocouple bead to be 160 W/m2 K. Assume conduction along the lead wires to be negligible.

A thermocouple is used to measure the temperature of hot gas flowing in a duct having a wall temperature of 700 K. The temperature indicated by the thermocouple is 900 K. Estimate the true temperature of the air. Take the duct walls to be effectively "black", the emissivity of the thermocouple bead to be 0.2 and the convective heat-transfer coefficient between gas and thermocouple bead to be 160 W/m2 K. Assume conduction along the lead wires to be negligible.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter11: Heat Transfer By Radiation

Section: Chapter Questions

Problem 11.54P

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