Ground Potential
Ground potential — also called earth potential or reference ground — is the baseline electrical potential of the Earth's surface, defined by convention as zero volts. All other voltage measurements in electrical systems are made relative to this reference point. The Earth maintains this stable reference potential through its enormous mass, its continuous replenishment of free electrons by atmospheric electricity, and its ability to absorb or supply electrons without measurable change in its own electrical state. When a grounding product connects the human body to the earth ground through a properly grounded outlet or grounding rod, it connects the body to this zero-volt reference — causing the body's elevated electrical potential (measurable as body voltage, typically 1 to 10V in modern indoor environments) to equalise toward zero. This voltage equalisation is what body voltage measurements with a multimeter directly confirm during grounding contact — the drop from an elevated body voltage to near-zero is the measurable signature of the body connecting to earth potential. GroundingMatrix covers the measurement process in detail in our <a href="https://groundingmatrix.com/blog/how-to-test-grounding-mat-conductivity">conductivity testing post</a>.