An infusion system (100, 170, 190, 210) for being operatively connected to a fluid delivery line and to an infusion container containing an infusion fluid, the infusion system comprising: a pump; at least one sensor (114, 172, 192, 212) connected to the pump or the fluid delivery line, the at least one sensor configured to indicate whether air is in the fluid delivery line; at least one processor in electronic communication with the pump and the at least one sensor, wherein the at least one sensor comprises a force sensor, and a memory in electronic communication with the at least one processor, wherein the memory comprises programming code for execution by the at least one processor, and the programming code is configured to determine air in the fluid delivery line based on force measurements taken by the force sensor and on multi-channel filtering of the force measurements from the force sensor and statistical process control charts (176, 196, 216) applied to the multi-channel filtered measurements, wherein the SPC charts comprises a cumulative sum control chart, and wherein the programming code is configured to estimate future measurements of the force sensor based on the multi-channel filtering of the measurements from the force sensor, determine a residual as a difference between an actual force measurement and the estimated future force measurement, construct the cumulative sum control chart based on the residual of the filtered measurements of the force sensor, the infusion system comprising a qualifier (180, 200, 220) comprising algorithms to be applied by the programming code of the processor to determine the air in the fluid delivery line based on the cumulative sum control chart and on infusion volume information (178, 198, 218). a pump; at least one sensor (114, 172, 192, 212) connected to the pump or the fluid delivery line, the at least one sensor configured to indicate whether air is in the fluid delivery line; at least one processor in electronic communication with the pump and the at least one sensor, wherein the at least one sensor comprises a force sensor, and a memory in electronic communication with the at least one processor, wherein the memory comprises programming code for execution by the at least one processor, and the programming code is configured to determine air in the fluid delivery line based on force measurements taken by the force sensor and on multi-channel filtering of the force measurements from the force sensor and statistical process control charts (176, 196, 216) applied to the multi-channel filtered measurements, wherein the SPC charts comprises a cumulative sum control chart, and wherein the programming code is configured to estimate future measurements of the force sensor based on the multi-channel filtering of the measurements from the force sensor, determine a residual as a difference between an actual force measurement and the estimated future force measurement, construct the cumulative sum control chart based on the residual of the filtered measurements of the force sensor, the infusion system comprising a qualifier (180, 200, 220) comprising algorithms to be applied by the programming code of the processor to determine the air in the fluid delivery line based on the cumulative sum control chart and on infusion volume information (178, 198, 218).