Schaeffler presents the lubricating grease sensor FAG GreaseCheck. Analysing the grease in ongoing operation can prevent damage from occurring to the rolling elements in good time and permits a shift to lubrication which is driven by requirements and not according to defined time periods. Initial uses of this sensor by leading manufacturers of wind turbines and large wind farm operators have shown that substantial cost savings and time economies can be achieved with this method for critical turbines which are very difficult to access. In addition, it is beneficial to the environment and resources and a higher degree of turbine utilisation is achieved. The sensor head, which measures just five millimetres in diameter, is embedded directly in the lubricant. Four parameters can be detected with the aid of the optical infrared reflection method: Water content, cloudiness, thermal or mechanical wear and temperature. An intelligent electronic evaluation system generates an analog signal from these, which informs the user about the condition of the grease both rapidly and simply. If a threshold value is set, a direct indication of whether the grease condition is good or poor can be provided by a signal. This allows suitable action to be taken immediately, right up to an emergency shutdown, in response to any changes in grease condition that may suddenly occur.