抄録
In the measurement of the pulmonary diffusing capacity DL by the single breath method the entire inspiration time has hitherto been included in the breath holding time. When the inspiration time is prolonged, this treatment leads to a considerable error in the DL value. In order to eliminate this error a correction factor of the inspiration time was newly introduced to obtain the effective inspiration time. The correction factor was a function of the ratio of the residual capacity to the total alveolar gas volume and the ratio of DL to the flow rate of inspiration. A nomogram was made for convenience to obtain the effective inspiration time.