Table 3. Accuracy of standard and enhanced Innocor gas analyser.

System T90 (ms)	FRC (L)	Mean (SD) percentage error in FRC
		Slow ventilation (10–12 min−1)	Medium (20–22 min−1)	Fast (31–32 min−1)
Fast 88	0.521	1.87 (0.77)	1.48 (0.73)	0.79 (0.27)
	1.011	1.15 (1.2)	0.94 (0.46)	0.40 (0.18)
	2.001	−0.06 (0.63)	0.04 (0.15)	0.21 (0.95)
Slow 154	0.521	0.07 (0.30)	−2.72 (0.81)	−8.33 (0.36)
	1.011	−0.30 (0.87)	−4.58 (0.24)	−8.89 (0.21)
	2.001	−1.65 (0.87)	−2.67 (0.12)	−5.91 (0.34)

Summary of error in functional residual capacity (FRC) calculated by multiple breath washout for a lung model at different FRC and ventilation rates. FRC are shown excluding the equipment dead space of 59 ml, and error is quoted as a percentage of the lung model FRC only (excluding deadspace). Precise ventilation rates varied with the lung model settings specific to each FRC and were 10.9, 21.8, 31.6 min⁻¹ for 0.5 L FRC, 10.8, 21.7, 31.5 min⁻¹ for 1 L FRC, and 11.8, 20.5, 31.3 min⁻¹ for 2 L FRC. T₉₀: 10–90% rise time of the gas analyser.