Method and apparatus for detecting and locating defects in a component of a turbine

In a method for the early detection and location of a change in a component of a turbine, in particular in a turbine blade, in the event of a deviation from a standard value in at least one measured value determined during operation of the turbine, an acoustic spectrum generated by the component is measured in the interior of the turbine and compared with a reference spectrum. In order to increase the intensity of signals in the acoustic spectrum, the components of the turbine, preferably runner blades, are excited from outside to acoustic emission (resonance test). An apparatus has a number of sensors for recording operating parameters of the turbine. The sensors are connected to a device for measured value conditioning. In order to detect and locate changes, an acoustic measurement probe which can be inserted from the outside into the interior of the turbine, is connected to the device.