The cone system measures the heat of the kiln and the length of firing.
The cone system measures the heat of the kiln and the length of firing. Cones are essential when firing to know when your kiln has reached the necessary temperature and to ensure the kiln is heated evenly. Each cone has a number assigned to it corresponding to a specific temperature range. For example, cone 03 indicates a temperature range of about 1,960 to 1,987 degrees Fahrenheit.