I have 4 ESD mats at the computer workshop I work. The ESD mats are interconnected and one of them is connected to ground through a resistive socket (or whatever it's called) which must be several Megaohms because my Ohmeter cannot read it (it reads up to 2MOhm). Yesterday I did this test: I used a voltmeter set to AC voltage, negative probe touching the ground in a socket, the other one between my fingers. I measured 2 volts. Then I put on the ESD wrist-band and I was surprised to find that not only did the voltage go down, it rose to 2.2volts!. It looks like this mat isn't working, am I right?