The computer grades are QFVC=F, QFEV1=F. Curve #1 (red) is rejected because of a large extrapolated volume. Curve #4 (green) has the largest FVC and FEV1 but is not repeatable (FVC and FEV1 are not within 150 ml of other acceptable curves). The computer FVC grade is F as only one curve has a plateau in the volume-time Curve #3 and the test is not repeatable -- 424 ml difference between largest and second larges FVC. However, Curve #1 may be used to confirm a complete inhalation as its FVC is the approximately the same as Curve #4. So, the FVC is validate by the rejected curve and raises the FVC F grade to a C. Similarly, Curve #1 confirms a complete inhalation for the FEV1 and the shapes of the other curves confirm a maximal effort at the start of the maneuver. Thus the FEV1 grade is raised from a F to a C as well, and the grades are QFVC=C and QFEV1=C.
