ESD test instruments: how do you verify an EPA?

Which instruments do you need to verify an EPA?

Verifying an EPA per DIN EN 61340‑5‑1 typically uses five instruments: a resistance and resistivity meter with electrodes, a combined wrist-strap and footwear tester, a walking test kit, an electrostatic field meter, and simple continuity or ground checkers. Each covers a different measured quantity.

What does each instrument measure and which thresholds apply?

The resistance meter checks whether surfaces and floors dissipate charge (resistance-to-ground typically below 1 GΩ). The strap tester covers 1 to 35 MΩ, the walking test caps body voltage below 100 V, and the field meter reveals residual fields. Your ESD control program sets the exact limits.

• Worksurfaces and floors: resistance-to-ground usually below 1 GΩ (10^9 Ω), measured with defined electrodes and test voltage.
• Wrist straps: person-strap-ground system resistance in the 1 to 35 MΩ (10^6 Ω) range; daily function test recommended.
• ESD footwear and floor together: resistance plus walking test, body voltage below 100 V.
• Field strength: keep conductive objects field-free, avoid insulators in the EPA or neutralise them with ionisation.
• Grounding: continuity of ground points and bonds kept low-ohmic, typically below 1 Ω.

How often must an EPA be verified?

Verification intervals follow the compliance verification plan: wrist straps are tested every working day, fixed elements such as floors and worksurfaces periodically (often yearly or half-yearly), and the instruments themselves must stay calibrated. All results are documented.

• Daily: wrist-strap test by the operator before starting work (tester or continuous monitoring).
• Periodic: resistance-to-ground of floors, worksurfaces, seating and shelving per the test plan.
• Yearly: calibration or verification of the measuring instruments themselves.
• Event-driven: re-measure after refit, cleaning with wrong agents or new materials.

Frequently asked questions