The fundamental temperature scale with its zero at absolute zero and expressed in degrees Kelvin. One degree Kelvin is equal to one degree Celsius or one degree Centigrade. For the purpose of practical calculations in order to convert Celsius to Kelvin add 273. It is normal for the degree Kelvin to be abbreviated in mathematical formulae to âKâ with the degree symbol being omitted.

A temperature scale based on the susceptibility of a paramagnetic substance, assuming that it obeys Curie's law; used at temperatures below about 1 kelvin.

Saturated Adiabatic Lapse Rate; the rate at which the temperature of water vapour saturated air changes as it ascends or descends. It is taken as 1.5 degree Celsius per 1000ft.

The temperature point below which a material, especially metal, is brittle; that is, the critical normal stress for fracture is reached before the critical shear stress for plastic deformation.

A measure of viscosity used in the tar industry, equal to the temperature in degrees Celsius at which the viscosity of tar is 50 seconds as measured in a standard tar efflux viscometer. Abbreviated EVT.