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High-Temperature Thermal Conductivity Measurement Apparatus Based on Guarded Hot Plate Method

  • E. Turzo-AndrasEmail author
  • T. Magyarlaki
TEMPMEKO 2016
  • 271 Downloads
Part of the following topical collections:
  1. TEMPMEKO 2016: Selected Papers of the 13th International Symposium on Temperature, Humidity, Moisture and Thermal Measurements in Industry and Science

Abstract

An alternative calibration procedure has been applied using apparatus built in-house, created to optimize thermal conductivity measurements. The new approach compared to those of usual measurement procedures of thermal conductivity by guarded hot plate (GHP) consists of modified design of the apparatus, modified position of the temperature sensors and new conception in the calculation method, applying the temperature at the inlet section of the specimen instead of the temperature difference across the specimen. This alternative technique is suitable for eliminating the effect of thermal contact resistance arising between a rigid specimen and the heated plate, as well as accurate determination of the specimen temperature and of the heat loss at the lateral edge of the specimen. This paper presents an overview of the specific characteristics of the newly developed “high-temperature thermal conductivity measurement apparatus” based on the GHP method, as well as how the major difficulties are handled in the case of this apparatus, as compared to the common GHP method that conforms to current international standards.

Keywords

Heat transfer High-temperature guarded hot plate Thermal conductivity Thermal contact resistance 

List of symbols

GH

guarded hot plate

HTTCMA

high-temperature thermal conductivity measurement apparatus

TCR, R

thermal contact resistance

\(\lambda \)

thermal conductivity

dQ(z)

heat flow in axial direction

dQp

heat loss in radial direction

A

metering area of the heater plate

\(t_{RS}(z)\)

temperature function in the metering zone

\(t_{RG}(z)\)

temperature function in the guard zone

tig

temperature of the inner surface of the gap

teg

temperature of the outer surface of the gap

\(\Delta \hbox {t}\)

temperature drop across the specimen

d

specimen thickness

\(t_{m}\)

mean temperature of the specimen

dt/dz

temperature derivative of the specimen

\(Pe_{MZH}\)

electrical power supplied to the heater plate

Q

heat flow at the inlet section of the specimen

Qg

heat flow loss at the guard-center gap

\(Qg_{t}\)

total heat flow loss across the center-guard gap

\(Qg_{l}\)

conductive heat flow across the gap

\(Qg_{R}\)

radiative heat flow across the gap

tis

temperature of the inlet section of the specimen

tos

temperature of the outlet section of the specimen

thp

temperature of the hot plate surface

tcp

temperature of the cold plate surface

q

density of heat flow rate

Ri

TCR at inlet section of the specimen

Ro

TCR at outlet section of the specimen

Notes

Acknowledgements

This work was funded through the European Metrology Research Programme (EMRP) Project SIB 52 “Thermo”—Metrology for Thermal Protection Materials. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.

References

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Copyright information

© Springer Science+Business Media, LLC 2017

Authors and Affiliations

  1. 1.Magyar Kereskedelmi Engedelyezesi Hivatal (MKEH)BudapestHungary

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