Questions about ESD mats

[openthomas]

I have the 3m 8200 series esd mat. I plan on hooking it to a ground from my radiator and also ground from my socket. The monitor requires 2 grounds (3m 732).

Is it unwise to use ground from the wall outlet ? Can I get shocked ?

How can I test the radiator ground to see if it is really earth ? And also how can I test the quality of the ground connection ?

Can a esd mat conduct and short pcbs laying on them ? Is it safe to power up pcbs resting on the surface ?

The 3m 732 ESD workstation monitor applies a voltage of 9v or 16v with < 3ua to test the mat is continually grounded. Can this effect powered pcbs laying on the surface ?

See page 4 here

http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTtMxMaoxF6EVuQEcuZgVs6EVs6E666666--

What is the better choice 9v or 16v ? And which is the safer option 10 megohms or 35 megohms ?

Thanks !

[notsob]

some reading for you
http://www.esdjournal.com/techpapr/eosesd/grounds/fsg.htm

and some testers
http://www.transforming-technologies.com/constant-monitors.html