Which of the following does NOT represent a form of pressure measured by fans?

Absolute pressure does not represent a form of pressure measured by fans in the context of HVAC systems and airflow dynamics. When discussing fan performance and operation, the focus is primarily on static pressure, velocity pressure, and dynamic pressure.

Static pressure refers to the pressure exerted by the air in a system when it is not in motion. It is crucial for determining how well the air can be distributed through ductwork and other components. Velocity pressure, on the other hand, measures the kinetic energy of moving air and is essential for understanding the speed of airflow. Dynamic pressure encompasses a combination of both static and velocity pressure, relating to the total pressure within the airflow system.

In contrast, absolute pressure is a measure of pressure relative to a complete vacuum, reflecting the total atmospheric pressure at a specific point. While absolute pressure is significant in other contexts, such as in measuring the pressure of gases or fluids in various industrial applications, it does not specifically relate to the performance metrics commonly associated with fans in air-moving applications. Thus, absolute pressure is the correct choice as it does not pertain to the forms of pressure directly measured by fans.