Temperature measurements in castings are carried out with thermocouples (TC’s), which are inserted in the melt. The TC influence solidification of the casting, especially in thin wall castings where the heat content of the melt is small compared to the cooling power of the TC. A numerical analysis of factors influencing temperature measurement in thin walled castings was carried out. The calculations are based on and compared with experiments presented in part 1 of this paper. The analysis shows that the presence of the TC has only a minor influence on the microstructure of the casting. The influence is restricted to a volume within 2mm from the TC. Measured cooling curves will have the right shape. In a 2 mm plate the measured temperature was 17 °C below the true temperature in the melt. However, the cooling curve provides important information about nucleation and growth during solidification.