Abstract: A valve position sensor (1) is described. The valve position sensor comprises a sensor housing (10) for placement on a moving component of a valve (12); a print circuit board assembly disposed within the housing, the print circuit board assembly comprising: one or more micro sensors, the one or more micro sensors including a magnetometer; a processing unit configured to receive data from the magnetometer and compare the received magnetometer data with predetermined calibration data to determine valve position data relating to an estimate of the valve position; and a transmitter for wirelessly transmitting event data including valve position data to an external receiver. The valve position sensor provides a low cost means to remotely determine the position of a valve.