It is difficult to measure the distribution of temperature or the development of solidified layer or the cooling rates of the real castings. Moreover, when there is a change in design or in positions or sizes of risers or chills. a new casting must be made every time to measure its temperature to know the changes in the distribution of temperature or the state of solidification.
  We have made an analog simulator by which the temperature and the change of temperature distribution of castings may be measured, which eliminates any need for making real castings. The simulator was designed as an electrical system from the requirement of a simple structure and easy measurement.
  It consists of number of unit blocks made up of condensers and resistances, the combination of which represents a casting. The heat of a casting is represented by the electric charge, which is discharged through the electric resistances corresponding to the heat resistance of casting, and the change of voltage is thus measured. The voltage corresponds to the temperature of casting.
  The influence of the latent heat of solidification is fed by another circuit, which is composed of a condenser and a resistance, connected to the main circuit. It acts when the voltage corresponds to solidification temperature.
  The simulator was made for aluminum castings and the change of temperature and the time necessary for the solidification of plates, square blocks and cross-shaped blocks of metal and sand mold castings were measured and their values were compared with the calculated values. They coincided very well and the experiment ended in success.
  This simulator is big, 125cm×185cm×30cm, but we are now trying to make a portable one. Simulators for cast iron and steel castings may be made in the same way simply by changing the resistances and the capacities of the condensers of the circuit.