The kit contains four aluminium discs, each having a different durable finish: Matt black, mirror black, matt silver and mirror silver. Bonded to the reverse of each disc is a Liquid Crystal thermometer measuring 30°C to 65°C in 5°C increments. The Liquid Crystal device on the disc is easy to read and shows how absorption of heat radiation depends on surface colour and texture. The disc reacts very quickly to a heat source such as infrared or a bright light, giving fast results, so more experiments can be completed in each lesson. The discs can be used to investigate rates of cooling, the effects of filters and reflectors, inverse square law and equilibrium between absorption and emission. The discs are supplied as a set of 4 with a holder in a storage box. Reading the temperature:. The indicated temperature is read when the segment is GREEN. When heating the disc the segments appear brown, then green, then blue, before returning to black. If STOP appears the heat source should be removed immediately.
