EH-15 Stefan-Boltzman Source
When used with the EG-45 Radiometer, this tungsten lamp provides a radiation source that can measure the energy radiated as a function of temperature. This relation was first set down from theoretical considerations by Stefan and Boltzmann. From the current through the lamp and the voltage across it, students can establish the filament resistance and hence the filament temperature. The energy varies over four decades so that the results are very convincing. |
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EG-45 Radiometer
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This instrument measures the total energy in the spectrum from the infrared to the ultraviolet. Calibrated in watts/square meter, it conveniently measures solar radiation. With the Stefan-Boltzman Source, it verifies Stefan's fourth power law of radiation versus temperature. |