Shear Stress Coverage over STL

Hi all,

I’ve calculated shear stress over my domain and displayed it on paraview. There is a very small section of my domain which has any shear stress values.

What I want to do is calculate how much area that actually covers. I know integrate variables calculates the coverage of my STL, but I can’t think of a way to calculate how much my patch of shear stress greater than zero covers.

Any help would be greatly appreciated