ISA Handbook of Measurement Equations and Tables, 2nd Edition

When measuring flow, physical properties of fluids and gases are significant when designing systems and measuring performance. Properties of fundamental importance include:
Temperature
Pressure
Liquid State
Gaseous State
Density
Viscosity
Specific Gravity
Depending on the type flowmeter used, and application, the following properties may also be important:
Vapor Pressure
Boiling Point
Electrical Conductivity
Sonic Conductivity
Velocity
Specific Heat