ABSTRACT
This chapter looks closely at some of the basic characteristics of fluids and how they are defined in terms of their mass, density, and viscosity. Particular attention is paid to the different methods of expressing these parameters both in terms of the SI metric units and the FPS system used extensively in the United States. It also explores the reaction of both liquids and gases to the effect of pressure variations. Attention is also paid to the concept of density and its measurement using both pycnometry and hydrometry as traceable standards. This chapter also explores the growth of different density measuring scales that are often unique to a specific industry for example American Petroleum Institute (API) gravity.
Considerable emphasis is placed on the concept of viscosity, its measurement, the difference between dynamic and kinematic viscosity, and the significance of different scales in different industries. This chapter also explores the difference between Newtonian and non-Newtonian fluids and their influence on flow measurement.
