A type of pyrometer for ceramic industry. Also called a Seger triangular pyramid.
It was invented by H.A.Seger (1839-1893) of the Royal Porcelain Manufactory in Berlin, Germany, in 1886. It is made of the same raw materials as porcelain, and a fixed scale is created based on the relationship between the chemical composition and melting temperature. The base of the triangular pyramid is set at about 80 degrees and viewed through a peephole. The melting temperature is measured in advance, so that the temperature inside the kiln can be determined. Ceramics do not burn well and melt well only with high heat. Even if the heat is relatively low, if it takes a long time, it will burn better than if it takes a short time at a high heat. Generally, firing in a small kiln and firing in a large kiln differ greatly in the way they burn and melt even at the same heat level, and even if the heat level is a little lower, the large kiln burns better. This is due to the time required for firing. Therefore, the temperature is not the only thing necessary for firing ceramics. In this respect, since the zeigel cone is composed of the same material as the fired object, its molten state is the same as that of the substrate in the kiln, so even if the temperature indicated is not exact, it is well suited to the fired state. The properties of ceramics are thus greatly affected by the state of heating and the state of melting, so when using a zegel pyramid, the exact temperature must be based on the standardized heating conditions. However, the actual heating conditions may not match this, so even though other pyrometers are much more accurate in terms of temperature, a zegel pyramid is closer to the true state of the product when it comes to the state of firing. This is the reason why the zegel pyramid is so important. Since all temperature measuring instruments only indicate the temperature of one area, it is necessary to use a large number of instruments in order to know the detailed condition of each part in the kiln. Therefore, since the light intensity produced by heating an object is very accurate, kiln builders should pay attention to the fire color first and foremost, and use instruments as a reference.
The current Zegel pyramid has undergone several revisions since Zegel. S.K8 means “Zegel cone No. 8. The others are the same as this. Today, it is manufactured by the Japan Segel Cone Association, and is commercially available after being certified by the Tokyo Industrial Testing Institute.
