Remmeber guys this is just an aid, it CANNOT read the TOTAL amount of downforce it is just giving you an idea as to what your changes (angle of attack and hieght etc) are doing, this newton reading along with your g dataloging allow the user to make an informed decision. Remmeber other forces like the boot latch, hinge mechanism and its affect on the leverage to the sensors all effect the readings.... it is a tool not a magician
One of the only ways i could find the total downforce would be to do two runs on a flat road, with pressure sensor's in between the rear strut tops and the body. Do one run as a control and log the results do another run with the wing at full deflection and minus the original results from the second.... this would give downforce as measured at the strut top... still not at the end user the wheels but for arguments sake fairly close.
It is based on a GT wing much like the sards and Voltex 3D wings, the 3d section allows the best comprimise between maximum downforce (more than std airfoil types) and minimum drag.