Pyrometric cones measure heat-work (the effect of time and temperature).

• Pyrometric cones are slender pyramids made from about 100 carefully controlled compositions.
• Each cone number is unique in measuring temperature within a small temperature range (less than 30°C).
• Cones measure the amount of heat absorbed.
• As the cone nears its maturing range, it softens and the tip begins to bend, drawn down by the influence of gravity.
• Cone Temperature Chart (printable pdf)