2. Scales of Metrology

Although not the topic of this book, commercial exchanges have been one of the first shared activities among humanity. Measurement, whether related to the object itself in terms of size, weight, or its functional characteristic such as performance, is one of the tools to reach agreement and satisfaction to allow transaction. To agree to a given transaction, the counterparty measures the value of the object if this is permissible. Because matter is active and functional at all scales, from less than an atom to very large-scale dimensions such as space, measurement science applies to all scales. This chapter discusses measurement techniques at these different scales and introduces the instruments that are dedicated to these scales. They have been specifically designed to perform these measurements.