How does PBE test for Capacity Under Pressure (C.U.P.)?

How does PBE test for Capacity Under Pressure (C.U.P.)?

After the product has been soaked in synthetic urine, pressure is applied to simulate the kind of pressure a wearer would exert on the saturated product. The amount of fluid remaining after pressure has been applied is defined as a C.U.P. capacity. Full 8oz. fluid cup measurement.