Newton scale

The Newton scale is a temperature scale proposed by Isaac Newton around the year 1700 . When Newton dealt with the problem area of heat , he developed the first qualitative temperature scale, which had around 20 points on the scale from "cold air in winter" to "glowing coals in the kitchen fire". This approach was crude and imprecise, so that Newton quickly became dissatisfied with it. Knowing the concept of thermal expansion , he used a vessel with linseed oil and measured its change in volume in relation to the earlier points on the scale. He found a volume increase of 7.25% between the temperature of melted snow and boiling water.

After a while he defined the zero point of his scale with melting snow ( melting point , 0 ° C) and the 33rd degree as boiling water ( boiling point , 100 ° C), so he used the same fixed points as the Celsius scale, only with different degrees. A difference of one degree Newton (1 ° N) therefore roughly corresponds to that of three degrees Celsius.

Temperature scales

Overview of the classic temperature scales

unit	Unit symbol	lower anchor point F 1	upper anchor point F 2	Unit value	inventor	Year of creation	Distribution area
Kelvin	K	Absolute zero point , T 0 = 0 K	Now without a fixed point, originally later T Tri ( H 2 O ) = 273.16 K ${\displaystyle 1\,\mathrm {K} \;{\stackrel {\mathrm {def} }{=}}\;1\,^{\circ }\mathrm {C} }$	${\displaystyle 1\,\mathrm {K} =1{,}380\,649\cdot 10^{-23}{\frac {\mathrm {J} }{k_{\mathrm {B} }}}}$ earlier ${\displaystyle {\frac {F_{2}-F_{1}}{273{,}16}}}$	William Thomson Baron Kelvin	1848	worldwide ( SI unit )
centigrade	° C	Now 0 ° C = 273.15 K, previously T Schm (H 2 O) = 0 ° C	Now coupling to Kelvin, previously T boiling (H 2 O) = 100 ° C	${\displaystyle 1\,^{\circ }\mathrm {C} \;{\stackrel {\mathrm {def} }{=}}\;1\,\mathrm {K} }$ earlier ${\displaystyle {\frac {F_{2}-F_{1}}{100}}}$	Different Celsius	1742	worldwide ( derived SI unit )
degrees Fahrenheit	° F	Now 32 ° F = 273.15 K, originally T cold. = 0 ° F, later T Schm (H 2 O) = 32 ° F	Now coupling to Kelvin, originally T human = 96 ° F, later T boiling (H 2 O) = 212 ° F	${\displaystyle 1{,}80\,^{\circ }\mathrm {F} \;{\stackrel {\mathrm {def} }{=}}\;1\,\mathrm {K} }$ originally later ${\displaystyle {\frac {F_{2}-F_{1}}{96}}}$ ${\displaystyle {\frac {F_{2}-F_{1}}{180}}}$	Daniel Fahrenheit	1714	United States
Rankine degree	° Ra, ° R	T 0 = 0 ° Ra	Now coupling to Kelvin	${\displaystyle 1\,^{\circ }\mathrm {Ra} \;{\stackrel {\mathrm {def} }{=}}\;1\,^{\circ }\mathrm {F} }$	William Rankine	1859	United States
Degree Delisle	° De, ° D	T Schm (H 2 O) = 150 ° De	T boiling (H 2 O) = 0 ° De	${\displaystyle {\frac {F_{1}-F_{2}}{150}}}$	Joseph-Nicolas Delisle	1732	Russia (19th century)
Degree Réaumur	° Ré, ° Re, ° R	T Schm (H 2 O) = 0 ° Ré	T boiling (H 2 O) = 80 ° Ré	${\displaystyle {\frac {F_{2}-F_{1}}{80}}}$	René-Antoine Ferchault de Réaumur	1730	Western Europe until the end of the 19th century
Degrees Newtons	° N	T Schm (H 2 O) = 0 ° N	T boiling (H 2 O) = 33 ° N	${\displaystyle {\frac {F_{2}-F_{1}}{33}}}$	Isaac Newton	≈ 1700	none
Degree Rømer	° Rø	T Schm ( Lake ) = 0 ° Rø	T boiling (H 2 O) = 60 ° Rø	${\displaystyle {\frac {F_{2}-F_{1}}{60}}}$	Ole Romer	1701	none
Notes on the table: ↑ T Tri (H 2 O) has been at 273.16 K since the redefinition in May 2019 with a relative uncertainty of 3.7 · 10 −7 according to Le Système international d'unités . 9e édition, 2019 (the so-called "SI brochure", French and English), pp. 21 and 133. ↑ The temperature of a cold mixture of ice, water and salmiak or sea salt (−17.8 ° C) and the supposed "body temperature of a healthy person" (35.6 ° C) were originally used ↑ The melting temperature of a brine (−14.3 ° C) was used.

Temperature conversion

Conversion between the temperature units

→ from →		Kelvin (K)	Degrees Celsius (° C)	Degrees Fahrenheit (° F)	Rankine degree (° Ra)
↓ to ↓
T Kelvin	=	T K	T C + 273.15	(T F + 459.67) 5 ⁄ 9	T Ra · 5 / 9
T Celsius	=	T K - 273.15	T C	(T F - 32) 5 ⁄ 9	T Ra · 5 / 9 - 273.15
T Fahrenheit	=	T K * 1.8 - 459.67	T C * 1.8 + 32	T F	T Ra - 459.67
T Rankine	=	T K * 1.8	T C * 1.8 + 491.67	T F + 459.67	T Ra
T Réaumur	=	(T K - 273.15) x 0.8	T C x 0.8	(T F - 32) 4 ⁄ 9	T Ra · 4 / 9 - 218.52
T Rømer	=	(T K - 273.15) 21 ⁄ 40 + 7.5	T C · 21 / 40 + 7.5	(T F - 32) 7 ⁄ 24 + 7.5	(T Ra - 491.67) 7 ⁄ 24 + 7.5
T Delisle	=	(373.15 - T K ) x 1.5	(100 - T C ) x 1.5	(212 - T F ) 5 ⁄ 6	(671.67 - T Ra ) 5 ⁄ 6
T Newtons	=	(T K - 273.15) x 0.33	T C x 0.33	(T F - 32) 11 ⁄ 60	(T Ra - 491.67) 11 ⁄ 60
→ from →		Degree Réaumur (° Ré)	Degree Rømer (° Rø)	Degree Delisle (° De)	Degree Newton (° N)
↓ to ↓
T Kelvin	=	T Ré 1.25 + 273.15	(T Rø - 7.5) 40 ⁄ 21 + 273.15	373.15 - T De · 2 / 3	T N · 100 / 33 + 273.15
T Celsius	=	T Ré 1.25	(T Rø - 7.5) 40 ⁄ 21	100 - T De · 2 / 3	T N · 100 / 33
T Fahrenheit	=	T Ré · 2.25 + 32	(T Rø - 7.5) 24 ⁄ 7 + 32	212 - T De 1.2	T N · 60 / 11 + 32
T Rankine	=	T Ré · 2.25 + 491.67	(T Rø - 7.5) 24 ⁄ 7 + 491.67	671.67 - T De * 1.2	T N · 60 ⁄ 11 + 491.67
T Réaumur	=	T Ré	(T Rø - 7.5) 32 ⁄ 21	80 - T De · 8 / 15	T N · 80 / 33
T Rømer	=	T Re · 21 / 32 + 7.5	T Rø	60 - T De 0.35	T N · 35 / 22 + 7.5
T Delisle	=	(80 - T Ré ) · 1.875	(60 - T Rø ) 20 ⁄ 7	T De	(33 - T N ) 50 ⁄ 11
T Newtons	=	T Re · 33 / 80	(T Rø - 7.5) 22 ⁄ 35	33 - T De · 0.22	T N