Abstract: Sensing systems are presented in which one or more sensors are operatively associated with a portable device such as a smartphone or tablet computer. A software application on the portable device provides an interface through which a user can interact with the sensors, e.g. to collect readings or perform calibrations. Preferably the portable device acts as an intermediary to a Cloud service for management and storage of measured data and calibration information. Once transmitted to the Cloud, the data can be accessed from any internet-connected device.