Experimental determination of Stefan's constant

1. Sep 8, 2011

dipu212

1. The problem statement, all variables and given/known data
I am using an apparatus to determine Stefan's constant using incandescent lamp and photovoltaic cell where the following formula is used.
Stefan's cont = 2.43 X 10 (-4) { Vs’/ T}
result in joule per sqr meter per sec per quad Kelvin.
Where Vs’ = Vo +Vs in volts with Vo volts corresponding to work function of photo cathode and Vs volt corresponding to maximum kinetic energy of photo electrons which in turn correspond to photon’s of maximum energy emitted by a black body at temperature T Kelvin ( temperature of the incandescent filament which acts as a black body radiator.
Vo= minimum work function , i.e. obtain from the intercept on the Y – axis obtain from the graph of Vs( mV) and T ( in Kelvin)
Vs = voltage of the photovoltaic cell obtain from multimeter.

2. Relevant equations
My problem is I did not find the above formula in any book. Can anybody tell me that where can I get the derivation of the formula

3. The attempt at a solution