Question

What is the Reaumur temperature scale? Give the advantage and disadvantage of Reaumur scale thermometer.

Answer 1

The Reaumur scale is a temperature scale in which the freezing and boiling points of water are defined as 0 and 80 degrees respectively. The scale is named after the physicist Rene Reaumur who created it in 1731.

The unit associated with the scale is called Reaumur, usually abbreviated "Re". The two base points of the scale are the melting point of ice and the boiling point of water, both at normal pressure. There are 80 degrees between those values, one degree Reaumur is the 80th part of that temperature difference.

Reaumur used ethanol for his thermometers. Thermometers that use ethanol show the change of temperature better than those using mercury. This is because, when heated, ethanol expands faster than mercury. There is the problem though that the expansion of ethanol is different at different temperatures - it is non-linear. Ethanol has a very low boiling point, which makes thermometers based on it unusable for many applications.