Standard
ANSI/ESD STM97.1-2025
System resistance measurement of a person, their footwear and the floor as one circuit. This is the test behind the S20.20 ceiling.
What it means for your floor
A 2025 edition, replacing 2015
The current edition is 2025 and it supersedes the 2015 one. If your program document cites the 2015 edition it is not wrong, it is simply on an older revision, and it is worth checking what changed before your next audit.
Why the person is in the circuit
Static leaves a facility through a person far more often than through the floor alone. Measuring the three together is the only way to know the actual path to ground works in the room, with the shoes people really wear.
What makes a system fail this
Usually not the floor. Worn footwear, a heel strap that has stopped making contact, or a floor finish applied over the system are the common causes, and every one of them is invisible until the reading is taken.
