Temperature measurement is very important to a whole range of areas and activities: science, scientific research, manufacturing, medicine and travel. Many businessmen and tourists from Europe, Asia, Africa are going to travel to the USA and UK, the countries that have not adopted the use of the modern metric system of measurements, called the SI system. The accepted base SI unit of temperature is the Kelvin. However, a change of 1 K is the same as 1 degree Celsius. As the degree Celsius is a convenient, easy to grasp in - every - day - life metric unit, therefore, both units are used in parallel. The Kelvin is used by scientists and engineers and the degree Celsius by everybody else in all countries. There are, however, two prominent exceptions: the USA and UK commonly use the Fahrenheit scale.
Daniel, Gabriel Fahrenheit, a German physicist was born in 1686 in Gdansk, Poland. The concept of the thermometer for measurement temperature changes is credited to Galileo. However, Fahrenheit is known for inventing the alcohol and mercury thermometers. His temperature scale is based on affixing 32º for melting point of ice and 212º for the boiling point of water under normal atmospheric pressure. The interval between two affixed points is being divided into 180 equal parts (the degrees Fahrenheit). The Fahrenheit scale had been in use by English speaking countries until the 1970.
The travellers to the USA and UK often are faced with the problem: how to convert efficiently the temperature in the degree Fahreneit to the temperature expressed in the degrees Celsius without a mistake and with a good aproximation.
The conversion formula "Fahrenheit to Celsius" is:
ºC = 5/9 (ºF - 32º) ; read:
"In order to express the temperature in the degrees Celsius, I need to divide 5 by 9 and multiply by the temperature in Fahrenheit lowered by 32º". Quite akward, isn't it?
Much simpler way, easier to remember and easier to perform mentally is to memorise the four following steps:
F→→→ C: "Subtract 32, divide by 2, add 10% ( or 1/10) of the result and add 1% of the total".
Let us see how it works:
E.g. 1: 98 ºF (your normal body temperature)→→→66 →→→33 →→→36.3 →→→36.7 ºC (rounded off to one decimal place).
E.g. 2: 102 ºF ( your possible body temperature)→→→70→→→35→→→38.5→→→38.9 ºC (high, pay visit to a doctor!).
Have a nice trip and keep warm!
NB.: The algorithm of conversion can be copied and distributed freely subject to the inclusion of the author's name and the author's website www.wacek.co.za
PS.: Have you read my former article: "The Travellers Temperature Predicaments"? Then, now, you will be able to find the answer to
the following puzzle:
FORGETFULNESS
A student solving a problem on transfer of heat found a correct temperature change. However, he presented the answer without a unit but as it turned out, it did not matter whether he gave the temperature with units in the degrees Fahrenheit or the degrees Celsius. The answer remained the same. What temperature was it? Please, do not guess, solve it!
The solution, you may find in the book: "SI Units, Conversion and Measurement Skills". If, however, you find the correct solution and send it to metricfun@gmail.com while purchasing my book, you will receive the second copy of the book FREE.
Wacek Kijewski is the author of the 2007 edition - "SI Units, Conversion and Measurement Skills" (186 pp); USD 19.95 (Amazon USD 218 and USD 361). Stimulating and entertaining resource material on experimental science matters. Strongly recommended for students and lecturers of post-16 science and engineering courses. Read seven reviews: UNESCO, UK, South Africa, Botswana, United States, Hungary. Subscribe to free "SI Newsletters"; solve "The da Vinci code" puzzle, buy one copy and get the second copy free. Website: http://www.wacek.co.za. The book from other boksellers/websites is illegal. His former articles: "How to Measure Cultural Differences in Metric Units", "Is IQ the Metric Unit of Intelligence and ... Stupidity?", "Al - Gebra and Illuminati Linked Discovered". Born in Poland, Wacek Kijewski studied electronics, telecommunication, acoustics and pedagogy. He taught science in Poland, Hungary and became Lecturer and Principal Tutor in Nigeria and Botswana.
