checking of deflection during meshing

hello everybody,
i got a question on the meshing process. i use to mesh a face the command:

BRepMesh::Mesh (myFace, myDeflection);

sometimes if the deflection is too low the application exits. my question: is there a minimum of deflection or is it dependent on the shape (what i guess). if the deflection is too low i get an segmentation error. can i handle somehow this with an exception to prevent a program exit? like:

try {
BRepMesh::Mesh (myShape, myDeflection);
}
catch (?????) {
cout (some error handling)
}

thanks for your help in advance!
Steve