You need the 1MEG resistor. It's purpose is to dissipate the charge at a non-instantaneous rate, protecting the electronic assembly and protecting the operator. James Head BEng MIET CID+ James Head PCB Design and Engineering 11 Charmind Walk,Winterbourne Road, SWINDON, SN25 1QA Telephone: 01793 266237 Mobile: 07870 945579 Skype: headjames E-mail: [log in to unmask] Website: www.jameshead.co.uk On Fri, 17 Aug 2018 at 21:32, Vargas, Stephen M <[log in to unmask]> wrote: > All: > > A quick ESD question. We would like to use 3'x4' static dissipated > anti-fatigue mats at our SMT lines. The floor under these mats are coated > with ESD wax and verified regularly. The question is whether the mats need > to be grounded with a 1 megohm resistor or will the static charge dissipate > naturally through the mat into the floor? Wiring is an option, but the > wires tend to get damaged frequently through normal operator movement. > Thanks in advance. > > Regards, > Steve Vargas >