Abstract: The invention relates to a method of determining a crack at an edge of a metallic material, the edge having a curvature with a radius. The method including: feeding and controlling a current to a transmitter coil for generating a magnetic field in the metallic material, detecting the magnetic field by means of a receiver coil, which detected magnetic field thereby generates a signal) in the receiver coil, determining first, second and third signal values of the signal at a first time, a second time and a third time, respectively, determining a possible presence of a crack and its crack depth based on the first, second and third signal values by means of determining a characteristic relation between the signal values.

Abstract: The invention relates to a method of determining a crack at an edge of a metallic material, the edge having a curvature with a radius. The method including: feeding and controlling a current to a transmitter coil for generating a magnetic field in the metallic material, detecting the magnetic field by means of a receiver coil, which detected magnetic field thereby generates a signal) in the receiver coil, determining first, second and third signal values of the signal at a first time, a second time and a third time, respectively, determining a possible presence of a crack and its crack depth based on the first, second and third signal values by means of determining a characteristic relation between the signal values.

Abstract: Pressure sensor for measurement of gas pressure in a cylinder of a combustion engine, including a tube shaped in cross section as an hourglass. In the axial direction the tube consists in part of a section connected to the cylinder and open to the cylinder, in part of a measuring section and in part of a final section the end of which is closed. The measuring section of the tube is shaped so that in the tubes axial direction two parallel measuring surfaces are established against which are two beams connected to force transferring yokes arranged to influence force measuring organs for the determination of the force with which the gas pressure influences the parallel measuring surfaces of the tube. In this pressure sensor and other embodiments the influences of temperature fluctuations and any shunting effects of the material of the measuring tube are reduced to a minimum.