Advantech ADAM-5510/P31 Manual page 189

3. Noise Reduction Techniques
4. Check Point List
Why we think the
EARTH as GROUND?
As you know that the EARTH can t be conductive indeed.
But those parallel resistors make the EARTH as a single
point and just for reference.
• Why we think the EARTH as GROUND?
As you know that the EARTH can not be conductive indeed. But all
buildings base on EARTH. Steels, concretion and relational cables
such as Lighting Arrester and power system were connected to
EARTH. Think them as resistors, then those infinite parallel resistors
make the EARTH as a single point and just for reference.