All continuous flow methods (SFA and FIA) have highly precise sample volumes and analysis times. While FIA injects with a valve, SFA injects by time. Each standard and sample is exposed to exactly the same conditions meaning that reactions in both FIA and SFA methods do not need to be carried to completion (steady state). In addition, it is the internal volume of the tubing (travel time) and the injection volume (peak width) that determine the analysis time per sample. SFA peaks do not broaden as they travel through the tubing. This means that in methods with large travel time SFA methods have faster analysis times, while in methods with small travel times the analysis time is essentially equal.