Sir Charles W. Shults III wrote:
Actually, they ARE supposed to be conductive- at least to the
tune of about a megohm. In any operation that is serious about
antistatic procedures, the mats, wrist straps, and other equipment
are to be tested periodically. Most testers show if a mat reads open
right away. If you have mats or other equipment that read open,
then you have found defective hardware. Trash it.

A mega-ohm per what unit of distance? From any point on the mat to the
ground point?