Radiation thermal resistance may be written as [where F, A, σ are shape factor, Area and Stefan-Boltzmann constant respectively]
1
\(\frac{1}{{FA\sigma \left( {{T_1} + {T_2}} \right)\left( {T_1^2 + T_2^2} \right)}}\)
2
\(\frac{1}{{FA\sigma \left( {{T_1} + {T_2}} \right)\left( {T_1^2 - T_2^2} \right)}}\)
3
\(\frac{1}{{FA\sigma \left( {T_1^4 - T_2^4} \right)}}\)
4
\(\frac{1}{{FA\sigma \left( {T_1^4 + T_2^4} \right)}}\)