University of North Texas Digital Library (University of North Texas) · 1954 · 13 citations · 0 references
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EngineeringChemical EngineeringMechanical EngineeringCombustionHeat TransferThermal AnalysisHeat ConductionHeat Transfer FundamentalsRadiative Heat TransferThermal Properties Of MaterialsThermal SensorsThermoelectric MaterialsExhaust EmissionsExhaust Gas EmissionsThermocouple InstrumentationThermocouple MeasurementThermocouple ThermometryThermocouplesThermoelectric Energy ConversionThermoelectric Properties
Thermocouples were exposed to exhaust gases from the combustion of propane, 72-octane gasoline, and JP-4 fuel. Exposure increased the emissivity of the thermocouple wire, which increased its radiation error. Two methods are presented for determining the emittance of the wires. The emissivity of a clean platinum rhodium-platinum thermocouple was approximately 0.2 in the temperature range investigated, while the emittance of an exposed thermocouple coated with exhaust residue was about 0.5. The exposure caused negligible change in the thermoelectric power of the thermocouples.