A spirometer that includes a sensor and a specifically designed flow chamber to create a pressure change and produce spirometry test results is disclosed. In one embodiment, the sensor comprises an absolute barometric pressure sensor. The spirometer of the present disclosure includes a single sensor positioned between the inlet of a flow chamber and a barrier to compute spirometry values with barometric pressure change. Pressure, humidity, and temperature are features that are built into the sensor. These sensor features and values assist in final computational spirometry test values as users complete test maneuvers.
