Stefan-Boltzmann’s law of radiation with an amplifier

螢幕截圖 2016-04-05 15.13.53

Item no.: P2350101

Principle

According of Stefan-Boltzmann’s law, the energy emitted by a black body per unit area and unit time is proportional to the power “four” of the absolute temperature of the body. Stefan-Boltzmann’s law is also valid for a so-called “grey” body whose surface shows a wavelength independent absorption-coefficient of less than one. In the experiment, the “grey” body is represented by the filament of an incandescent lamp whose energy emission is investigated as a function of the temperature.

Tasks

  1. To measure the resistance of the filament of the incandescent lamp at room temperature and to ascertain the filament’s resistance R0 at zero degrees centrigrade.
  2. To measure the energy flux density of the lamp at different heating voltages. The corresponding heating currents read off for each heating voltage and the corresponding filament resistance calculated. Anticipating a temperature-dependency of the second order of the filament-resistance, the temperature can be calculated from the measured resistances.

What you can learn about

  • Black body radiation
  • Thermoelectric e. m. f.
  • Temperature dependence of resistances