Scope and field of application

This International Standard specifies a method for determining the pyrometric cone equivalent (refractoriness) of siliceous, low alumina fireclay and fireclay refractory materials and products.

Its useful range of application depends on the availability of suitable pyrometric reference cones. In the temperature range from 1 500 to 1 800 °C, the pyrometric reference cones specified in ISO/R 1146 are suitable.

Although pyrometric reference cones are primarily manufactured for estimating the effect of temperature on siliceous, low alumina fireclay and fireclay products with regard to their composition, the method may also be used for determining the refractoriness of other refractory materials and products, but the results may then be not so precise.