The measurement of the pressure on the surface of an object with fluid flow present is important in determining the behavior of fluid flow and calculating the forces imposed by the flow on an object. For example, the shock wave that forms on the upper surface of a commercial transport wing in cruise conditions can be located by knowing the surface pressure distribution. By knowing the pressure distribution over the surface of an automobile, ventilation inlets can be appropriately placed. Aircraft designers determine expected loads by measuring surface pressures on wind-tunnel models and integrating the corresponding forces over the entire surface of the model.