A spirometer for sensing fluid flow from an individual breathing through the spirometer, the spirometer comprising: a tubular housing having an open first end and an open second end, the housing defining a first fluid flow pathway extending between the first end and the second end, a first opening along the first fluid flow pathway and through which fluid flow enters, and a second opening longitudinally spaced along the first fluid flow pathway from the first opening and through which fluid flow enters; a flow chamber having a central longitudinal axis and defining a second cylindrical fluid flow pathway, the flow chamber being disposed within the housing between the first opening and the second opening, the flow chamber including an elongated cylindrical resistive element along the central longitudinal axis of the flow chamber, and at least one elongated cylindrical tubular element disposed concentrically with the resistive element between the resistive element and the inner surface of the flow chamber for defining a plurality of annular flow passages through the flow chamber between the resistive element and the inner surface of the flow chamber, and a plurality of branched flow passages longitudinally spaced along the tubular element for interconnecting the annular flow passages, wherein the resistive element and the at least one tubular element direct fluid flow through the annular passages of the flow chamber for conditioning fluid flow for accurate sensing of the flow over a range of fluid flow through the housing; and a pressure sensor disposed within the housing, the pressure sensor in fluid communication with the first opening and the second opening for sensing a pressure differential between the first opening and the second opening and producing an electric signal in response to fluid flow through the housing, wherein the electric signal has a magnitude that corresponds with the rate of fluid flow through the housing and a sign that corresponds with the directionality of fluid flow through the housing. a first fluid flow pathway extending between the first end and the second end, a first opening along the first fluid flow pathway and through which fluid flow enters, and a second opening longitudinally spaced along the first fluid flow pathway from the first opening and through which fluid flow enters; a flow chamber having a central longitudinal axis and defining a second cylindrical fluid flow pathway, the flow chamber being disposed within the housing between the first opening and the second opening, the flow chamber including an elongated cylindrical resistive element along the central longitudinal axis of the flow chamber, and at least one elongated cylindrical tubular element disposed concentrically with the resistive element between the resistive element and the inner surface of the flow chamber for defining a plurality of annular flow passages through the flow chamber between the resistive element and the inner surface of the flow chamber, and a plurality of branched flow passages longitudinally spaced along the tubular element for interconnecting the annular flow passages, wherein the resistive element and the at least one tubular element direct fluid flow through the annular passages of the flow chamber for conditioning fluid flow for accurate sensing of the flow over a range of fluid flow through the housing; and a pressure sensor disposed within the housing, the pressure sensor in fluid communication with the first opening and the second opening for sensing a pressure differential between the first opening and the second opening and producing an electric signal in response to fluid flow through the housing, wherein the electric signal has a magnitude that corresponds with the rate of fluid flow through the housing and a sign that corresponds with the directionality of fluid flow through the housing. a flow chamber having a central longitudinal axis and defining a second cylindrical fluid flow pathway, the flow chamber being disposed within the housing between the first opening and the second opening, the flow chamber including an elongated cylindrical resistive element along the central longitudinal axis of the flow chamber, and at least one elongated cylindrical tubular element disposed concentrically with the resistive element between the resistive element and the inner surface of the flow chamber for defining a plurality of annular flow passages through the flow chamber between the resistive element and the inner surface of the flow chamber, and a plurality of branched flow passages longitudinally spaced along the tubular element for interconnecting the annular flow passages, wherein the resistive element and the at least one tubular element direct fluid flow through the annular passages of the flow chamber for conditioning fluid flow for accurate sensing of the flow over a range of fluid flow through the housing; and a pressure sensor disposed within the housing, the pressure sensor in fluid communication with the first opening and the second opening for sensing a pressure differential between the first opening and the second opening and producing an electric signal in response to fluid flow through the housing, wherein the electric signal has a magnitude that corresponds with the rate of fluid flow through the housing and a sign that corresponds with the directionality of fluid flow through the housing.