In this lesson you will learn about the general data in the API Technical Data Book in Chapter 1. General Data covers unit conversions, chemical engineering symbols, physical property definitions, and basic information used every day in your engineering work. The first section on units of measure includes information on the fundamental constants and basic units of length, area, volume, mass, density, flow conversions, kinematic, absolute viscosity, energy conversions, power conversions, specific energy, heat flux, heat transfer and thermal conductivity. Letter symbols used in chemical engineering are an easy way for new engineers to check for unknown symbols and to quickly build your vocabulary to use symbols and equations. Property definitions provide a brief summary of each physical property and describe what the property is and how it is reported, calculated or estimated within the API Technical Data Book. This will conclude our lesson on Chapter 1: General Data in the API Technical Data Book.