A reservoir assembly for storing hydrogen peroxide for use with a hydrogen peroxide vaporizer in association with a filler, the reservoir assembly comprising: - a fluid chamber having an elongated body with an inner surface having a substantially uniform cross-sectional configuration along at least a portion thereof, the fluid chamber defining a lower end and an upper end; - an overflow sensor positioned proximate the fluid chamber and spaced apart from the upper end of the fluid chamber and a low level sensor positioned proximate the fluid chamber and spaced apart from the lower end of the fluid chamber, and positioned between the overflow sensor and the lower end of the fluid chamber; characterised in that the reservoir assembly further comprises: - a float member positioned within the fluid chamber and slidably movable toward and away from each of the lower end and the upper end of the elongated body, the float member having a target region at a top surface thereof, and an outer surface structurally configured to define a plurality of passageways between the outer surface of the float member and the inner surface of the fluid chamber, with at least one sidewall guide surface configured to slidably interface and guide the float member in slidable movement along the inner surface of the elongated body, the float member having a density such that the float member is at least partially submerged hydrogen peroxide when hydrogen peroxide is placed within the fluid chamber, while at least the target region remains above the level of the hydrogen peroxide; - a fluid column level sensor positioned at a top end of the fluid chamber, the sensor configured to determine the position of the float member by interfacing with the target region of the float member. - a fluid chamber having an elongated body with an inner surface having a substantially uniform cross-sectional configuration along at least a portion thereof, the fluid chamber defining a lower end and an upper end; - an overflow sensor positioned proximate the fluid chamber and spaced apart from the upper end of the fluid chamber and a low level sensor positioned proximate the fluid chamber and spaced apart from the lower end of the fluid chamber, and positioned between the overflow sensor and the lower end of the fluid chamber; - a float member positioned within the fluid chamber and slidably movable toward and away from each of the lower end and the upper end of the elongated body, the float member having a target region at a top surface thereof, and an outer surface structurally configured to define a plurality of passageways between the outer surface of the float member and the inner surface of the fluid chamber, with at least one sidewall guide surface configured to slidably interface and guide the float member in slidable movement along the inner surface of the elongated body, the float member having a density such that the float member is at least partially submerged hydrogen peroxide when hydrogen peroxide is placed within the fluid chamber, while at least the target region remains above the level of the hydrogen peroxide; - a fluid column level sensor positioned at a top end of the fluid chamber, the sensor configured to determine the position of the float member by interfacing with the target region of the float member.