Table 2– Methodological aspects of the transfer factor of the lung for nitric oxide (TL,NO) measurement in five reference studies
van der Lee [13]Aguilaniu [20]Zavorsky [21]Phansalkar [29]Dressel [26]
TechniqueSingle breathSingle breathSingle breathRebreathingSingle breath
Commercial systemMasterLab Pro (Erich Jaeger)HypAir (Medisoft+)HypAir (Medisoft)Masterscreen PFT (Viasys§)
NO analyser
 MakeChemiluminescence CLD 77AM (Eco Physicsƒ)Electrochemical cell (Medisoft)Electrochemical cell (Medisoft)Sievers nitric oxide analyzer 280 (Sievers Instruments, Inc.##)Electrochemical cell (Viasys)
 SpecificationLower limit 0.02 ppb
Upper limit 10 ppm
Response time 0.1 s
Lower limit 0.1 ppm
Upper limit 450 ppm
Response time <10 s
Lower limit 0.1 ppm
Upper limit 450 ppm
Response time <10 s
Response time <0.5 sUnknown
NO source750 ppm in N2450 ppm in N2450 ppm in N2448 ppm in N2
FI,NO ppm84040c. 4045
Other gases %
 Carbon monoxide0.250.280.280.30.28
 Helium9.179.47 or 149.47 or 149.5
 Oxygen19 or 2119 or 2130
 Methane0.3
 Acetylene#0.4–0.8
 Balance gasAirN2N2N2Air
Breath hold time s1045.516 (rebreathe)8
Discard volume mL750800900NA750
Sample volume mL750600900NA750
  • FI,NO: inspiratory nitric oxide fraction; NA: not available; #: used for measuring total pulmonary blood flow; : Erich Jaeger, Friedberg, Germany; +: Medisoft, Dinant, Belgium; §: Viasys, Hoechberg, Germany; ƒ: Eco Physics, Zurich, Switzerland; ##: Sievers Instruments, Inc., Boulder, CO, USA.