Stefan Boltzman Apparatus

The apparatus is designed to determine the Stefan Boltzman constant. The apparatus consists of a hemisphere fixed on a backlite plate, the outer surface is surrounded by a hot water jacket. Hot water to heat the tank is obtained from a hot water tank with heater fixed above hemisphere. Hot water jacket heats the hemisphere and this heat is transferred to a small copper test disc by radiation. This small test disc can be introduced at the center of hemisphere. A thermocouple is provided at the canter of disc to measure the temperature of disc. With the help of Timer/Stop Clock change in temperature with respect to time can be recorded. The average temperature of hemisphere can be measured by four thermocouples placed on hemisphere.


Easy understanding of phenomenon of heat transfer by radiation.
Determination of Stefan Boltzman constant.
Built in timer for temperature measurement at constant intervals.


  • Hemisphere made of copper, 200 mm dia, approx.
  • Hot water jacket.
  • Test Disc - 20 mm dia., 1.5 mm thick, copper
  • Hot water tank with heater.

Instrumentation & Controls :

  • Multy channel Digital Temperature Indicator.

Experimentation :

  1. Determination of Stefan Boltzman Constant.
  2. Study of effect of hemisphere temperature on the constant.

Service Required :

  • 230 V.A.C. stabilized supply with earthing.
  • Floor space - 1.5 m X 1.5m at working height.


Stefan Boltzman Apparatus with thermocouples - Jagajeet marketing and