Česky (CZK)Personnel and grounding testing in an EPA
People are a major potential source of electrostatic charge in an EPA. Personnel testing verifies whether a wrist strap, ESD footwear or another grounding method provides an effective path for controlled charge dissipation.
What does a personnel tester actually verify?
A tester does not assess whether a person is “ESD qualified”. It checks the electrical function of a specific grounding system at the moment of the test. Depending on the workplace, this may cover a wrist strap, the left and right shoe or several elements together.
- Wrist strap: the result includes skin contact, the cuff, coil cord and relevant connections.
- ESD footwear: the path through the person and the individual shoe or foot grounder to the test electrode is measured.
- Person–footwear–floor system: an entry tester cannot always replace system verification; dynamic performance is assessed with a walking test.
Entry testing or continuous monitoring?
An entry tester provides a result at a defined moment, often before entering the EPA. A continuous monitor supervises the worker's connection and, depending on the system, the workstation throughout the task. The choice depends on process risk, device sensitivity, work organization and the ESD control plan. Passing an entry test does not by itself prove that the system remains unchanged for the entire shift.
How to establish a reliable process
- Define who tests what, when and on which instrument.
- Set the correct mode and limits for the grounding system and internal requirements.
- Train personnel in fitting wrist straps, standing on electrodes and responding to a failed test.
- Decide whether results are recorded manually, electronically or linked to access control.
- Document the failure process, including retesting, equipment checks and an approved alternative.
- Verify the tester itself regularly and follow the defined calibration or functional-check schedule.
Why did the test fail?
Possible causes include poor cuff-to-skin contact, a damaged cord, an incorrectly fitted wrist strap, contaminated or worn soles, unsuitable socks or insoles, incorrect foot placement or the wrong tester mode. A failure should be handled according to the defined procedure, not by repeating the test until it happens to pass.
Testing is only one part of the system
Personnel grounding must work together with the workstation, floor and handling procedures. See personnel grounding in the glossary for the fundamentals. Suitable equipment includes personnel grounding testers and continuous monitoring. The process can be evaluated as part of an ESD audit; related methods are listed under ESD measurement and verification.
