A fire suppression system , comprising: a cylinder having a wall defining an inner chamber ; and a processor operable to determine an amount of a suppressant in the inner chamber based on a capacitance between a first electrode and a second electrode that are both in contact with the suppressant; and a siphon tube disposed within the inner chamber and spaced apart from the wall comprising opposing first and second ends, the first end coupled to an output of the cylinder , the second end proximate to a base portion of the wall , the cylinder including a gap (G) between the second end and the base portion, wherein one of the first and second electrodes includes the siphon tube, and the other of the first and second electrodes includes the wall; each of the first electrode and second electrode is also in contact with a pressurant in the inner chamber ; the capacitance is an effective capacitance based on a first capacitance between the first and second electrodes with the suppressant as a dielectric medium, a second capacitance between the first and second electrodes with the pressurant as a dielectric medium, and a stray capacitance of each of the siphon tube and the wall indicative of a size of the gap (G); and the determination of the amount of suppressant in the inner chamber is based on: a radius (R 2 ) of the siphon tube ; a radius (R 1 ) of the cylinder ; a dielectric constant of the suppressant; a dielectric constant of the pressurant ; and a size of the gap (G) between the base portion of the cylinder and the second end of the siphon tube. a cylinder having a wall defining an inner chamber ; and a processor operable to determine an amount of a suppressant in the inner chamber based on a capacitance between a first electrode and a second electrode that are both in contact with the suppressant; and a siphon tube disposed within the inner chamber and spaced apart from the wall comprising opposing first and second ends, the first end coupled to an output of the cylinder , the second end proximate to a base portion of the wall , the cylinder including a gap (G) between the second end and the base portion, wherein one of the first and second electrodes includes the siphon tube, and the other of the first and second electrodes includes the wall; each of the first electrode and second electrode is also in contact with a pressurant in the inner chamber ; the capacitance is an effective capacitance based on a first capacitance between the first and second electrodes with the suppressant as a dielectric medium, a second capacitance between the first and second electrodes with the pressurant as a dielectric medium, and a stray capacitance of each of the siphon tube and the wall indicative of a size of the gap (G); and the determination of the amount of suppressant in the inner chamber is based on: a radius (R 2 ) of the siphon tube ; a radius (R 1 ) of the cylinder ; a dielectric constant of the suppressant; a dielectric constant of the pressurant ; and a size of the gap (G) between the base portion of the cylinder and the second end of the siphon tube. a radius (R 2 ) of the siphon tube ; a radius (R 1 ) of the cylinder ; a dielectric constant of the suppressant; a dielectric constant of the pressurant ; and a size of the gap (G) between the base portion of the cylinder and the second end of the siphon tube. <EOS>