Ceramic pyrometric cone equivalent

Because of the heterogeneity of their composition and structure, ceramic refractories do not exhibit a uniform melting point. The refractoriness is characterized by the optical determination of the pyrometric cone equivalent (according to Seger), that is, the temperature at which the tip of a cone made of the sample material softens to the point that it touches the base plate. Reference cones with well-established pyrometric cone equivalents at temperature intervals of 10 °C and above, along with the test cones made from the sample material, are heated in the same furnace so that it is possible to make an accurate comparative temperature determination for the softening point of the refractory material to within approximately 20 °C. 

DIN 51063. Testing of ceramic raw and finished materials. Pyrometric Seger cone. Part 1 determination of the bending point (pyrometric cone equivalent), Part 2 testing of Seger cones. ISO 1146 1988 Pyrometric reference cones for laboratory use - specification. 

Ceramic grade - Grades for ceramics are finely groimd (typically 200, 270, or 400 mesh), controlled for PCE (pyrometric cone equivalent), free of dark impurities, and white-firing without specking. 

Ortbosificates. See silicate structures. Orton Cones, pyrometric cones (q.v.) made by the Edward Orton Jr. Ceramic Foundation, Columbus, Ohio. They are made in two sizes 2Vt in. (63.5 mm) high for industrial kiln control, and 1 l/8th in. (29 mm) high for P.C.E. testing. For nominal equivalent softening temperatures see Appendix 2. Osborn-Shaw Process. See shaw process. Osmosis. See electro-osmosis. 

---