The rationale behind standardizing the physical test set-up is to isolate the equipment’s response to the ESD event itself. By strictly controlling the laboratory environment, equipment placement, and grounding configuration, the procedure effectively eliminates confounding variables and ensures the ultimate validity of the test results.

A central component of the test set-up is the ground reference plane (GRP), which must meet the following requirements:

• Material: Metallic sheet (copper or aluminium)
• Minimum Thickness: 0.25 mm
• Size: Must project beyond the equipment under test (EUT) on all sides by at least 0.5 m

The EUT must be placed on an insulating support with a thickness of 0.1 m, which is in turn placed upon the GRP. The discharge generator is earthed by connecting its discharge return cable directly to the GRP; the total length of this cable is in general 2 m. To prevent unintended coupling, all interconnecting cables for the EUT must be kept at a distance of at least 0.1 m from the GRP.

This static physical setup provides the controlled environment for the dynamic actions of the test procedure.