ABSTRACT
This chapter focused on measurement because in the teaching of physics, the insights achieved as a result of studying measurements are often taught as secondary to insights derived from theoretical approaches to a subject. Kilogram is a unique piece of platinum–iridium alloy kept at the International Bureau of Weights and Measures, Paris. It has its own special symbol, a gothic letter ‘K’, which refers the object itself and not its mass. All rational physicists use the system of units known as the International System of Units, or Le Systeme International d'Unites, or more normally SI units. Time, or its inverse, frequency, can be measured with stupendous accuracy. The ease with which high resolution is achieved for time and frequency measurements has caused people to seek ways to convert the quantity they wish to measure into a time measurement. The most important example of this is the development of techniques for measuring voltage, i.e. electrical potential difference.
