Good and Bad measurements with the ESD Garments

Technical Questions
#1

Dear ESD specialists

I have a good and a bad measurement for the same ESD garments ( wich i found weird) when i mesure the cuff to cuff resistor with my giga ohmmeter (the only measuring device in my possession actually) i have a good measurement R =20 G Ohm , but when i apply ANSI/ESD S1.1 test procedure to verify that the total series resistance of all of the elements in the personnel grounding with garment system, using the same device, the result was bad R= 11G Ohm , does it mean that the garments are bad enough and we should change the supplier, ( some of them are new and have never been used ), or mabe next time we would have to specify the characteristics concerning garments?

Salutations

#2

The measurements here really depend on the type of ESD garment that you have. There are three types of garments, one, static control garments, two, groundable static control garments and three static control garment systems.
The first, static control garment, only has to meet a point to point or panel to panel resistance. There may not be a connection to the person. If this is the type of garment that you have, the results are as expected.
The second type, groundable static control garments will have a connection to ground, usually a snap, that has panel to panel resistance and a panel to groundable point resistance. Again, there may or may not be a connection to a person.
The third type, groundable garment system, has a built in wrist strap system. For this to work, the connection from a person to the groundable point needs to be less than 35 Mohms.
If you just have a static control garment, the results that you have is not a surprise.

If you have anymore questions, please feel free to post them.

1 Like
#3

Dear Mr John,

Thank you for your help ,i will ask the purchasing department to fill me all the documentation about about garments

best regards