抄録
An apparatus of spherical shell type of the radius s of a few mm having uniformly distributed point heat sources on its surface is used for measuring thermal conductivity.
The thermal conductivity is given by the equation
k=q0/4πθ·1/s_??_
on the assumption of no heat loss, Θ∞ being the temperature rise of the center of the shell after infinite time, q0 the heat input per unit time.
Correction for the heat loss through the lead wires of the heater and thermocouples is performed by the equation k_??_k+b√km, where km is the thermal conductivity by the aforementioned equation assuming no heat loss, k the true conductivity and b a certain constant of the apparatus. This equation is derived by the condition of heat conservation q0=ql∞+q∞ at infinite time where ql∞ is the heat loss through leads and q∞ the heat input to the shell, both per unit time.
