Advantech ADAM-5000/TCP Series - C.1 Grounding; Figure C-1: Think the EARTH as GROUND

Grounding Reference
Appendix C
C.1 Grounding
1-1 The ‘Earth’ for reference
Figure C-1: Think the EARTH as GROUND. As you
know, the EARTH cannot be conductivC. However, all buildings lie on,
or in, the EARTH. Steel, concrete and associated cables (such as
lighting arresters) and power system were connected to EARTH. Think
of them as resistors. All of those infinite parallel resistors make the EARTH
as a single reference point.
ADAM-5000/TCP User’s Manual
C-3