A1 Symbols and Units

1 Introduction: Legal Units

“The International Committee for Weights and Measures” (BIPM, Paris) publishes the “SI Brochure” [1]. Most of the base and derived units used in this VDI-Heat Atlas are SI units and are assorted below. The SI units are the units that are recognized globally in order to establish a worldwide dialog and can be seen in the further reading. Although there are a variety of non-SI units for the same quantity in the literature, only some of them can be found below due to the fact that not all of them are widely used [2, 3].

As of October 2007, there are 51 Member States of the Metre Convention and 25 Associate States and Economies of the General Conference.

2 SI Base Units of Base Quantities

Quantity	Symbol of the quantity	Unit	Symbol of the unit
Length	L, x, y, z, r,…	Meter	m
Mass	M, m	Kilogram	kg
Time	t	Second	s
Electric current	I, i	Ampere	A
Thermodynamic temperature	T	Kelvin	K
Amount of substance	N	Mol	mol
Luminous intensity	I v	Candela	cd

3 SI Derived Units...