Table. 6—

Range and accuracy recommendations specified for forced expiratory manoeuvres

Test	Range/accuracy (BTPS)	Flow range L·s⁻¹	Time s	Resistance and back pressure	Test signal
VC	0.5–8 L, ±3% of reading or ±0.050 L, whichever is greater	0–14	30		3-L Calibration syringe
FVC	0.5–8 L, ±3% of reading or ±0.050 L, whichever is greater	0–14	15	<1.5 cmH₂O·L⁻¹·s⁻¹ (0.15 kPa·L⁻¹·s⁻¹)	24 ATS waveforms, 3-L Cal Syringe
FEV₁	0.5–8 L, ±3% of reading or ±0.050 L, whichever is greater	0–14	1	<1.5 cmH₂O·L⁻¹·s⁻¹ (0.15 kPa·L⁻¹·s⁻¹)	24 ATS waveforms
Time zero	The time point from which all FEV_t measurements are taken			Back extrapolation
PEF	Accuracy: ±10% of reading or ±0.30 L·s⁻¹ (20 L·min⁻¹), whichever is greater; repeatability: ±5% of reading or ±0.15 L·s⁻¹ (10 L·min⁻¹), whichever is greater	0–14		Mean resistance at 200, 400, 600 L·min⁻¹ (3.3, 6.7, 10 L·s⁻¹) must be <2.5 cmH₂O·L⁻¹·s⁻¹ (0.25 kPa·L⁻¹·s⁻¹)	26 ATS flow waveforms
Instantaneous flows (except PEF)	Accuracy: ±5% of reading or ±0.200 L·s⁻¹, whichever is greater	0–14		<1.5 cmH₂O·L⁻¹·s⁻¹ (0.15 kPa·L⁻¹·s⁻¹)	Data from manufacturers
FEF_25–75%	7.0 L·s⁻¹, ±5% of reading or ±0.200 L·s⁻¹, whichever is greater	±14	15	Same as FEV₁	24 ATS waveforms
MVV	250 L·min⁻¹ at V_T of 2 L within ±10% of reading or ±15 L·min⁻¹, whichever is greater	±14 (±3%)	12–15	<1.5 cmH₂O·L⁻¹·s⁻¹ (0.15 kPa·L⁻¹·s⁻¹)	Sine wave pump

BTPS: body temperature and ambient pressure saturated with water vapour; VC: vital capacity; FVC: forced vital capacity; ATS: American Thoracic Society; FEV₁: forced expiratory volume in one second; FEV_t: forced expiratory volume in t seconds; PEF: peak expiratory flow; FEF_25–75%: mean forced expiratory flow between 25% and 75% of FVC; MVV: maximum voluntary ventilation; V_T: tidal volume.