Main recommendations for spirometry
| Procedure | Recommendations |
| Body posture | Upright position |
| Start-of-test criteria | Extrapolation volume <100 mL or 5% FVC, whichever is greaterPEF sharp and close to maximum inflation.Steep upslope of the FVL |
| End-of-test criteria | Forced expiration lasting a minimum 6 s |
| Inspiration preceding the forced expiration | Fast and with no hesitation with breath-holding time at maximum inflation <1 s |
| Forced expiratory manoeuvre | No cough in the initial 1 sNo tongue obstructing the mouthpieceNo cessation of flow due to glottis closure or decreased effortNo leaks, no drift |
| Manoeuvres n | A minimum of three to a maximum of eight |
| Repeatability | Three technically satisfactory manoeuvres with the largest FEV1 and FVC not exceeding the next highest values by >5% or 0.1 L, whichever is greater. |
FVC: forced vital capacity; PEF: peak expiratory flow; FVL: flow-volume loop; FEV1: forced expiratory volume in one second.