The Long-Term Stability of Portable Spirometers Used in a Multinational Study of the Prevalence of Chronis Obstructive Pulmonary Disease, Perez-Padilla et al. Resp Care 2006
Ninety-seven percent of the calibration volumes were within +- 64 mL (2.1 %) of the 3-L calibration signal. Excluding data from the first cit y studied (Sao Paulo), where one calibration syringe had to be replaced, 98 % of the calibration checks were within ñ 50 mL (1.7 %). The measured volume was affected only minimally by the syringes peak flow or emptying time. Conclusion:In these 70 EasyOne spirometers neither calibration nor linearity changed during the study. Such calibration stability is a valuable feature in spirometr y surveys and in the clinical setting.