Question

What is correct: To mention temperature in deg K (°K) or in just K?

Asked by: Prof. C. F. Desai

 Answer

The correct one is just K, not degrees K.

The confusion arises due to the other common temperatures scale, the Celsius scale (based on the old Centigrade scale). This scale was derived from getting a mercury-in-glass thermometer and marking the ice-point and steam-point on it. The distance between these points is then divided into 100 divisions or degrees. The units used here are thus called degrees Celsius.

However, Kelvin, the SI unit of temperature, is based on the triple point of water (The temperature where water can exist in all 3 states). 1 K = 1/273.16 of the triple point of water. Kelvin, as an SI unit is similar to the metre and the second, and we don't say degrees metre, or degrees second do we?

Note from the editor: Degree K or °K was actually used in the past but it became obsolete by international agreement in 1967.

Answered by: Simon Hooks, Physics A-Level Student, Gosport, UK

Search

Loading



Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department

Science Quote

'As long as men are free to ask what they must; free to say what they think; free to think what they will; freedom can never be lost and science can never regress. '

J. Robert Oppenheimer
(1904-1966)

Deal of the Day

Image of Newtons Cradle - Large - 7 inches. Click on this image for more info. Newtons Cradle - Large - 7 inches
Regular Price: $24.95
Today's Price: $16.00
This classic desk toy will keep you amused! Large, 7 inch tall version. Buy it now! Deal ends at midnight!

Top Selling

Here are our physics & astronomy bestsellers:
Tin Can Robot 4M Kit
Deluxe 3D Mirascope
Periscope
Solar Radiometer
Potato Clock 4M Kit
Clean Water Science 4M Kit
Glowing Gel Experiment Kit
Magnetic Levitator - Classic
Ultimate Chemistry Set CHEM C3000 v2.0
KonusScience 5 Way Microscope Kit