Fuente: Wipo "Sensorization" A locomotive sensor system includes a sensor configured to be in contact with lubricant within an engine of a locomotive. The sensor includes a sensing region circuit that is configured to generate stimuli at different times during an operational life of the engine. The system also includes one or more processors configured to receive signals from the sensor. The signals are representative of responses of the lubricant to the stimuli. The one or more processors are configured to analyze the responses and determine a characteristic of the lubricant that represents one or more of a total base number (TBN) or a total acid number (TAN) of the lubricant. The are configured to determine an unhealthy state of one or more of the engine or the lubricant based on the characteristic of the lubricant that is determined.