An equipment for calibration of an industrial robot which has a plurality of axes of rotation and wherein, the equipment comprises a measuring device is adapted for rotatable connection to a reference point the position of which is known, is adapted to be in contact with the robot, or a tool carried by the robot, during the calibration process, and has an axis of rotation which intersects the reference point when the measuring device is connected to the reference point. The measuring device further comprises a gravity sensor which is so mounted so that the axis of the gravity sensor is substantially parallel to the axis of rotation of the measuring device, whereby the gravity sensor measures the angle between the gravity vector and axis of rotation.