How do ESD monitors work ?

Community Chit Chat
1

Hi everyone,

I want to understand how do ESD monitors work, those that detect if someone is wearing an ESD wrist strap or not and give signals to remind you to wear it. Well i know many methods but all of them work with the dual wire wrist band, therefor it is not hard to detect a person with two wires feedback. But the problem is that i need to work with the one wired wrist band and i don’t know how can you measure anything from just one wire.

I’ve read that the human body acts like a capacitor forming an RC circuit when wearing the wrist band and if you run some tiny AC current through this circuit, there will be a displacement current.

But still i can’t figure out how can you use this information to detect if someone is wearing the wrist band or not

2

Operators plug their ESD coil cord into the grounding jack of the constant monitor right at their workstation. The constant monitor grounds the wrist strap and simultaneously monitors for faults in the ground path from the strap to the earth ground, including proper contact with the operators skin.