Pyrometric Witness Cones are used to measure temperature inside a kiln. With the help of witness cones it is possible to determine if the kiln is firing at the correct temperature to properly mature your clay or glaze.
The cones are self-supporting, do not require cone holders and are made from highly controlled refractory material, making them the most accurate and easiest to use witness cones available.
Self-Supporting Cones are available for use between 586C and 1708C. Cones are numbered from 022 to 32. Cone 022 is the cone that will deform at the lowest temperature (586C) and cone 32 is the cone that deforms at the highest temperature 1708C.
A correctly fired cone will bend over with the tip of the cone almost touching the shelf, allowing you to easily determine at a glance, if the firing was successful.