Cramer D, Peacock A, Denison D
Thorax. 1984 Oct;39(10):771-4. doi: 10.1136/thx.39.10.771.
Forced expiratory volume (FEV1) and forced vital capacity (FVC) were measured in nine normal subjects with three Vitalograph and three rolling seal spirometers at three different ambient temperatures (4 degrees C, 22 degrees C, 32 degrees C). When the results obtained with the rolling seal spirometer were converted to BTPS the agreement between measurements in the three environments improved, but when the Vitalograph measurements obtained in the hot and cold rooms were converted an error of up to 13% was introduced. The error was similar whether ambient or spirometer temperatures were used to make the conversion. In an attempt to explain the behaviour of the Vitalograph spirometers the compliance of their bellows was measured at the three temperatures. It was higher at the higher temperature (32 degrees C) and lower at the lower temperature (4 degrees C) than at the normal room temperature. These changes in instrument compliance could account for the differences in measured values between the two types of spirometer. It is concluded that the ATPS-BTPS conversion is valid and necessary for measurements made with rolling seal spirometers, but can cause substantial error if it is used for Vitalograph measurements made under conditions other than normal room temperature.
在三个不同环境温度（4摄氏度、22摄氏度、32摄氏度）下，使用三台维达肺活量计和三台滚动密封式肺量计，对九名正常受试者测量用力呼气量（FEV1）和用力肺活量（FVC）。当将滚动密封式肺量计获得的结果换算为体温、气压、饱和水蒸气压（BTPS）时，三种环境下测量结果之间的一致性得到改善，但对在热室和冷室中获得的维达肺活量计测量结果进行换算时，会引入高达13%的误差。无论使用环境温度还是肺量计温度进行换算，误差都相似。为了解释维达肺活量计的表现，在这三个温度下测量了其波纹管的顺应性。与正常室温相比，在较高温度（32摄氏度）下顺应性较高，在较低温度（4摄氏度）下顺应性较低。仪器顺应性的这些变化可以解释两种类型肺量计测量值之间的差异。得出的结论是，对于滚动密封式肺量计的测量，体温、环境气压、饱和水蒸气压（ATPS）到体温、气压、饱和水蒸气压（BTPS）的换算有效且必要，但如果用于在正常室温以外条件下进行的维达肺活量计测量，可能会导致重大误差。
