DEVICE AND METHOD FOR MEASURING A MAGNETIC FIELD IN AN AIR-GAP BETWEEN A STATOR AND A ROTOR OF AN ELECTRIC MACHINE

1 . A device for measuring a magnetic field in an air-gap between a stator and a rotor of an electric machine, the device comprising a probe to detect the magnetic field and generate a signal indicative thereof and a display unit for the signal, wherein the probe includes a plurality of sensors.

2 . The device of claim 1 , wherein the plurality of sensors are aligned along at least one row.

3 . The device of claim 1 , wherein the sensors include inductive sensors, preferably inductive coils.

4 . The device of claim 1 , wherein the sensors include Hall sensors and/or magneto-resistive sensors.

5 . The device of claim 1 , wherein the sensors have different sensitivity in different directions.

6 . The device of claim 1 , wherein the sensors define two or more superposed layers.

7 . The device of claim 1 , wherein the probe includes a support that carries the sensors.

8 . The device of claim 7 , wherein the support is a flexible support.

9 . The device according to claim 1 , further comprising an excitation unit for generating a localised magnetic field.

10 . The device of claim 1 , further comprising at least one infrared sensor.

11 . A method for measuring a magnetic field in an air-gap between a stator and a rotor of an electric machine, the method comprising providing a device according to claim 1 , magnetizing at least a portion of the stator, moving the device on the stator bore, detecting the magnetic field generated by eddy currents that are generated by interlamination short circuits in the stator.

12 . The method according to claim 11 , further comprising magnetizing the whole stator.

13 . The method according to claim 11 , further comprising locally magnetizing the stator.