Table. 2—

Equipment specifications

Volume accuracyATS/ERS standards (currently 3.5% accuracy over an 8-L volume using test gases, with a testing syringe accuracy of 0.5%)
Gas analysersLinear from zero to full span within ±0.5% of full span. Stable over the duration of the test with drift <±0.5% of a measured gas
Circuit resistance<1.5 cmH2O·L−1·s−1 at a flow of 6 L·s−1
Demand-valve sensitivity<10 cm H2O required for 6 L·s−1 flow through valve and circuit (if compressed gas source used)
Timer±1.0% over 10 s (100 ms)
Apparatus/valve filter VD<0.350 L
  • ATS: American Thoracic Society; ERS: European Respiratory Society; VD: dead space volume.