Rømer scale

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Rømer is a disused temperature scale named after the Danish astronomer Ole Christensen Rømer, who proposed it in 1701.

In this scale, the zero was initially set using freezing brine. The boiling point of water was defined as 60 degrees. Rømer then saw that the freezing point of water fell at roughly one eighth of that value (7.5 degrees), so he used that value as the other fixed point. Thus the unit of this scale, a Rømer degree, is 40/21sts of a kelvin (or of a Celsius degree). The symbol is sometimes given as °R, but since that is also sometimes used for the Rankine scale, the other symbol °Rø is to be preferred. The name should not be confused with Réaumur.

Daniel Gabriel Fahrenheit learned of Rømer's work and visited him in 1708; he improved on the scale, increasing the number of divisions by a factor of four and eventually establishing what is now known as the Fahrenheit scale, in 1724.

Degree Rømer
Kelvin [K] = ([°Rø] − 7.5) · 40/21 + 273.15 [°Rø] = ([K] − 273.15) · 21/40 + 7.5
Celsius [°C] = ([°Rø] − 7.5) · 40/21 [°Rø] = [°C] · 21/40 + 7.5
Fahrenheit [°F] = ([°Rø] − 7.5) · 24/7 + 32 [°Rø] = ([°F] − 32) · 7/24 + 7.5
Rankine [°Ra] = ([°Rø] − 7.5) · 24/7 + 491.67 [°Rø] = ([°Ra] − 491.67) · 7/24 + 7.5
Réaumur [°Ré] = ([°Rø] − 7.5) · 32/21 [°Rø] = [°Ré] · 21/32 + 7.5
Newton [°N] = ([°Rø] − 7.5) · 22/35 [°Rø] = [°N] · 35/22 + 7.5
Delisle [°De] = (60 − [°Rø]) · 20/7 [°Rø] = 60 − [°De] · 7/20

Degree Rømer
Kelvin	[K] = ([°Rø] − 7.5) · 40/21 + 273.15	[°Rø] = ([K] − 273.15) · 21/40 + 7.5
Celsius	[°C] = ([°Rø] − 7.5) · 40/21	[°Rø] = [°C] · 21/40 + 7.5
Fahrenheit	[°F] = ([°Rø] − 7.5) · 24/7 + 32	[°Rø] = ([°F] − 32) · 7/24 + 7.5
Rankine	[°Ra] = ([°Rø] − 7.5) · 24/7 + 491.67	[°Rø] = ([°Ra] − 491.67) · 7/24 + 7.5
Réaumur	[°Ré] = ([°Rø] − 7.5) · 32/21	[°Rø] = [°Ré] · 21/32 + 7.5
Newton	[°N] = ([°Rø] − 7.5) · 22/35	[°Rø] = [°N] · 35/22 + 7.5
Delisle	[°De] = (60 − [°Rø]) · 20/7	[°Rø] = 60 − [°De] · 7/20

Comparison of temperature scales

Comparison of temperature scales
Comment	Kelvin	Celsius	Fahrenheit	Rankine	Delisle	Newton	Réaumur	Rømer
Absolute zero	0	−273.15	−459.67	0	559.725	−90.14	−218.52	−135.90
Coldest recorded surface temperature on Earth (Vostok, Antarctica - July 21, 1983)	184	−89	−128.2	331.47	283.5	−29.37	−71.2	−39.225
Fahrenheit's ice/salt mixture	255.37	−17.78	0	459.67	176.67	−5.87	−14.22	−1.83
standard pressure)	273.15	0	32	491.67	150	0	0	7.5
Average surface temperature on Earth	288	15	59	518.67	127.5	4.95	12	15.375
Average human body temperature ¹	309.95	36.8	98.24	557.91	94.8	12.144	29.44	26.82
(Al 'Aziziyah>Al 'Aziziyah, Libya - September 13, 1922)	331	58	136.4	596.07	63	19.14	46.4	37.95
standard pressure)	373.15	100	212	671.67	0	33	80	60
Titanium melts	1941	1668	3034	3494	−2352	550	1334	883
surface of the Sun	5800	5526	9980	10440	−8140	1823	4421	2909

¹ Normal human body temperature is 36.8 °C ±0.7 °C, or 98.2 °F ±1.3 °F. The commonly given value 98.6 °F is simply the exact conversion of the nineteenth-century German standard of 37 °C. Since it does not list an acceptable range, it could therefore be said to have excess (invalid) precision. Here's a [list] of various measurements.
Some numbers in this table have been rounded off.

External link

[A Brief History of Temperature Measurement]

Temperature scale (measurement)>scales
Celsius		Fahrenheit		Kelvin
Delisle	Leyden	Newton	Rankine	Réaumur	Rømer
Conversion formulas

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