The computer grades are QFVC=A, QFEV1=D. The lower computer FEV1 grade is due to a lack of a repeatable FEV1 (closest FEV1 is 203 ml). Curve #1 (black) is larger than the other curves possibly due to a better inhalation -- it has the largest FVC and FEV1. Because of the similarity between the curves, particularly the very repeatable peak flows, the FEV1 grade is increased to a C -- QFVC=A and QFEV1=C.
