Influence of thermocouple on temperature fields
Abstract
Thermocouples are widely used for measuring temperature. However, there are some possible errors which may be caused by the heat conduction of a thermocouple itself, radiation from its surroundings, defects and/or defective instrumentation of the thermocouple, and for other reasons. An analogy is used between temperature and electric potential fields. Carbon-paper i.e. Teledeltus paper was used for making the analogical model. Local nonuniformity of the thermal conductance in the temperature field was simulated in the electric field by distributing small holes and/or applying electric conductor paints on the carbon-paper. The physical boundary-conditions, such as distributions of heat transfer rate, and temperatures at the outer edge of flow boundary layers, were also simulated by the electric resistance and potential distributions on the boundary of the model. Measurements were made for a practical model of an air-cooled airfoil with 14 thermocouples. The results of the measurements are given, and the influences are discussed.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- July 1975
- Bibcode:
- 1975STIN...7619399N
- Keywords:
-
- Temperature Distribution;
- Temperature Measurement;
- Thermocouples;
- Boundary Conditions;
- Boundary Layers;
- Electric Fields;
- Heat Transfer;
- Simulation;
- Thermal Conductivity;
- Instrumentation and Photography