Celsius Celsius The Celsius scale, also known as the centigrade scale, is a temperature scale used by the International System of Units (SI). As an SI derived unit, it is used by all countries except the United States, the Bahamas, Belize, the Cayman Islands and Liberia. It is named after the Swedish astronomer Anders Celsius (1701–1744), who developed a similar temperature scale. The degree Celsius (°C) can refer to a specific temperature on the Celsius scale or a unit to indicate a difference between two temperatures or an uncertainty. Before being renamed to honor Anders Celsius in 1948, the unit was
Time–temperature superposition indicator of the quality of a relationship that has been computed from experimental data. The principle of time-temperature superposition requires the assumption of thermologically simple behavior (all curves have the same characteristic time variation law with temperature). From an initial spectral window ["ω", "ω"] and a series of isotherms in this window, we can calculate the master curves of a material which extends over a broader frequency range. An arbitrary temperature "T" is taken as a reference for setting the frequency scale (the curve at that temperature undergoes no shift). In the frequency range ["ω", "ω"], if the temperature increases