ASTM E 1105-00 (2008) "Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference".
This the Test Standard used for the AAMA 502 field
This International Test Standard is designed to produce a continuous and uniform film of water across the exterior surface of the test specimen. The testing apparatus is calibrated to produce a specific amount of water per square foot, per hour, over the specimen surface area.
An interior negative air pressure chamber that simulates the pressure dynamics of a wind-driven rain is constructed and connected to the interior surface of the window-wall interface, then accurately depressurized to meet the Engineered Test Specification.