Stefan–Boltzmann Law

Measure the radiant Intensity of a "black body".

In the experiment, a cylindrical electric oven with a burnished brass cylinder is used as a “black body”. The brass cylinder is heated in the oven to the desired temperature between 300 and 750 K. A thermocouple is used to measure the temperature. A water-cooled screen is positioned in front of the oven to ensure that the setup essentially measures only the temperature of the burnished brass cylinder. The measurement is conducted using a Moll’s thermopile; its output voltage provides a relative measure of the radiated power M. The thermopile can be connected either to an amplifier or, via the μV box, to the CASSY computer interface device. In the former case, the measurement must by carried out manually, point by point; the latter configuration enables computer-assisted measuring and evaluation. The aim of the evaluation is to confirm Stefan-Boltzmann’s law.

Electric oven
Black body accessory
Safety connection box with ground
Support for electric oven
Digital thermometer with one input
Temperature probe NiCr-Ni, 1.5 mm
Moll's thermopile
Microvoltmeter
Small optical bench
Stand base V-shape, large
Leybold multiclamp (4)
Universal clamp 0...80 mm
Connecting lead 19 A, 100 cm, red/blue, pair
Immersion pump 12 V
Low-voltage power supply
Silicone tubing, 7 mm diam., 1 m
Wide-mouthed can, 10 l