Abstract: A photoelectric oscillator includes a laser beam projection unit; an optical modulator on an optical path extending from the projection unit, which optical modulator outputs a modulated signal or an optical signal containing a harmonic of the modulated signal and includes a modulation electrode whose resonant frequency band includes the frequency band of the modulation signal; a photoelectric converter for converting the output of the optical modulator to an electric signal; a feedback circuit for selecting from the radio-frequency electric signal obtained from the photoelectric converter an electric signal to be re-supplied to the optical modulator; and an output section for outputting an optical signal containing the modulation signal or a harmonic of the modulation signal or outputting the modulation signal or a harmonic of the modulation signal.

Abstract: A method and apparatus for measuring a liner thickness of a zirconium liner provided at the inner surface of a zirconium alloy tube, the principle of measurement of which is to insert coils into the tube to generate an eddy current, detect the impedance component in the direction perpendicular to the direction of coil impedance change caused by the lift-off variation between the coils and the inner surface of tube, and obtain the liner thickness on the basis of the impedance component. In a case where the lift-off variation is larger, the impedance component in the direction of coil impedance change caused by the lift-off variation is detected, so that the component is used to correct the impedance component perpendicular to the same, thereby obtaining the liner thickness in accordance with the corrected values.

Abstract: A flaw detection apparatus for detecting flaws at the outer surface of a product, such as a steel bar, wire or steel pipe, which is round in section and produced by the hot rolling, by use of a probe of non-contact type and rotating around the product to be inspected, the apparatus providing a means for suppressing vibrations of an object to be inspected, a means for measuring a distance (lift-off) between the object to be inspected and the probe, and a means for carrying out positional control on the basis of the detection result of the lift-off measurement so that the axis of rotation of probe is allowed to be coincident with the axis of object to be inspected.

Abstract: A flaw detecting unit inspects the surface of a red-hot steel material, the nail marking unit drives steel nails into the flaw in response to the flaw detection signal, and a scarfing unit scarfs the flaw starting from the nails in response to the scarfing command signal.

Abstract: Surface defects occurring periodically in specific regions of the surface of steel material are removed by moving a detector head having a scarfing torch disposed forwardly of a detector probe for scanning along a predetermined path, during which the surface of the scanning path is scarfed smooth and detected by said head, and the surface defects are scarfed away according to the results of the detection.

Abstract: A cutting apparatus lights the surface of a moving hot steel material with lamps, locates any flaw with a video camera or the like, scarfs the surface of the steel material adjacent the flaw with a scarfing torch, measures the depth of the flaw with an eddy current detecting probe or the like, estimates accurately the loss of length due to conditioning size and depth of the flaw with a computer, and cuts the steel material in a predetermined length plus the accurately estimated length corresponding to the loss of length due to conditioning.