Oil diagnosis system

An oil diagnosis system including a controller configured to diagnose a machine on a basis of sensor data about a viscosity, a density, and a dielectric constant of oil, the sensor data being acquired via an oil property sensor mounted in the machine,

• the sensor data being used to obtain, for each of the viscosity, density, and dielectric constant of the oil, a moving average obtained by sequentially determining time-series average values, an amount of change per unit time, and a difference of an amount of change between values at different sensing points in time,
• the controller comprising:
• a storage section configured to store abnormality determination values for the moving average, the amount of change per unit time, and the difference of the amount of change between values at different sensing points in time, the abnormality determination values each being specified for a corresponding one of the viscosity, density, and dielectric constant of the oil;
• an abnormality determining section configured to determine abnormality of the oil on a basis of the moving average, the amount of change per unit time, and the difference of the amount of change between values at different sensing points in time, determined from the sensor data, and the abnormality determination values stored in the storage device in association with the moving average, the amount of change per unit time, and the difference of the amount of change between values at different sensing points in time;
• and
• a cause identifying section configured to identify, when the abnormality determining section determines the abnormality, a cause of the abnormality of the oil on a basis of any of the moving average, the amount of change per unit time, and the difference of the amount of change between values at different sensing points in time that correspond to an oil property determined to be abnormal, the oil property being one of the viscosity, the density, and the dielectric constant;
• and
• a transmission section configured to transmit, to an external terminal, a result for the cause of the abnormality identified by the cause identifying section.