An ESD wrist strap is the most common personal grounding device on an electronics line, and also the one most often trusted without proof. Because a strap can look perfectly fine while its cord has failed inside, testing is the only way to know it works.
How do you test an ESD wrist strap?
Use a wrist-strap tester: put the strap on, plug the cord into the tester, and press to read PASS or FAIL. The tester checks the full loop, which is skin contact, band, cord, and resistor, in one step. A daily touch-test at a station tester takes only seconds.
How often should you test it?
Test at the start of every shift, and again after any drop or damage. For critical work, a continuous monitor watches the loop all day and alarms the moment it breaks, so you are not relying on memory.
What a FAIL usually means
- Too high: a broken cord, a dried-out band, or loose skin contact, so replace the band or cord.
- Too low: a shorted resistor, which removes the safe current-limiting path, so replace the cord.
- Intermittent: a cracked cord that passes at rest and fails in motion, so use a continuous monitor to catch it.
A strap can also pass its test and still let damage through, which we cover in why a wrist strap that passes can still damage components. Phil Industries stocks ESD wrist straps and testers for electronics, medical, and OEM lines.
Frequently asked questions
Can I just look at a wrist strap to check it? No; the failure is usually inside the cord, so only a tester or continuous monitor confirms the loop.
What resistance should a wrist strap read? Testers are pre-set to the accepted band and simply show PASS or FAIL, so you do not need to read ohms at the bench.
Setting up ESD control for your line? Contact Phil Industries at kenneth@phil-industries.com or WhatsApp +65 9853 9030.
