* Spirometry* VC measurement should have < 3% error2.91 to 3.09 would be acceptable3L x .03 = .09L3 -.09 = 2.913 + .09 = 3.09 Obstructive PFT findings DECREASED flow studies DLCO and FEV1 decreased by 83% or greater less than 70% of FVCand increased TLC, FRC or RV. Restrictive ...