A sensor module for monitoring an asset in an electrical power generation or distribution system includes a module body, a sensor, a sensor near field coupling structure, and an interrogation near field coupling structure. The sensor is supported by the module body, arranged to sense a parameter of the asset and configured to generate a sensor output relating to the parameter. The sensor near field coupling structure is connected to the sensor and supported on a first side of a module body. The interrogation near field coupling structure is supported on a second side of the module body. The sensor output is transmitted from the sensor near field coupling structure to the interrogation near field coupling structure. The sensor module is configured to provide electrical isolation between the asset and a monitoring circuit configured to receive the sensor output through the interrogation near field coupling structure.