I just finished hooking up my new service to my home. As I was grounding the service disconnect panel, I got wandering. Is there a good way to check for a good ground at the ground rod.

In the past installations I have done, I use the reccomended ground rod for the soil type and area. (example - 5/8" x 10' for sand) If in doubt, I always go bigger. But is there a way to check to see if that is sufficient. Thanks, Kevin