A sparger for injection of bubbles into a flotation system comprises a housing, a movable rod assembly, and a sensor system that comprises a sensor and a target that move relative to each other. One of the sensor and the target is located in the housing and the other is located on or attached to the movable rod assembly. The sensor for measuring motion, including position and vibration, relative to the target based on the movement of the movable rod assembly. The sensor system for determining operating parameters of the sparger based on the analysis of the measurement of the motion of the sensor relative to the target.

An aerosol provision device includes a microphone configured to detect a flow of air in the device and to output corresponding airflow detection signals to control circuitry. The control circuitry is configured to determine a duration of an inhalation by a user of the aerosol delivery device based on the airflow detection signals received from the microphone.

A sparger for injection of bubbles into a flotation system comprises a housing, a movable rod assembly, and a sensor system that comprises a sensor and a target that move relative to each other. One of the sensor and the target is located in the housing and the other is located on or attached to the movable rod assembly. The sensor for measuring motion, including position and vibration, relative to the target based on the movement of the movable rod assembly. The sensor system for determining operating parameters of the sparger based on the analysis of the measurement of the motion of the sensor relative to the target.

Provided is a leakage detector which is capable of exhibiting high sensitivity to vibration-sounds caused by water leakage from a synthetic resin pipe and thus setting an installation span longer to thereby make it possible to more efficiently perform a water leakage inspection for a synthetic resin pipe. The leakage detector (6) comprises a base (21), a piezoelectric element (9) supported by the base (21) and configured to convert vibration-sounds to an electric signal, and a weight member (28) loaded against the piezoelectric element (9). The piezoelectric element (9) is made of a polymeric piezoelectric material. One end of the piezoelectric element (9) is supported by an upper end of a support post (27), and the weight member (28) is loaded against the other end of the piezoelectric element (9).