how can I get the correct volume value and the body resistance!

In joule heating model of 3D with comsol 4.3, using the measure tool, I can't get the volume value, only displaying as follows "Domains: 1. Faces: 8. Edges: 12. Points: 6. CAD objects: 1.", How can i get the volume value,such as 1M^3 for the cubic of length 1m;

In the results ,using the volume integration of domain index, I can't get the correct result.can you tell me why?

except this ,how can I get the resistance of the body?

Thanks a lot!