Abstract: Light is introduced to an inner surface of a fine tube, which is an object for measurement of the inner surface roughness, through a first end of the fine tube at a small angle with respect to a center line of the fine tube and the light emerging from a second end of the fine tube after the light is reflected by multiple reflections within the fine tube is measured to evaluate the roughness of the inner surface of the fine tube. Upon such measurement, the light to be introduced to the first end of the fine tube is converged once on the center line of the fine tube and then diverged again, and the polarization direction of the light to be introduced to the first end of the fine tube is set to an angle equal to or around 90 degrees with respect to the reflection surface of the fine tube. Thus, the roughness of the inner surface of the fine tube can be calculated in accordance with a result of detection of the intensity of emergent light from the fine tube by means of a photo detector.

Abstract: A method of nondestructively inspecting a magnetic substance such as metal pipe and bar stocks, wherein the method provides a detection coil having a diameter which is specified based on the length of existent peripheral surface flaws such that the directional sensitivity of the detection coil relative to those flaws is improved. The magnetic substance is moved along an axis thereof and has an eddy current induced therein. Relative rotation of the detection coil around the magnetic substance is effected to permit detection of surface flaws.

Abstract: A pneumatic pipe leak tester which includes: a compressed air source; a conduit of a first circuit connectible through an on-off valve to a pipe to be examined and provided with an electromagnetic valve; a conduit of a second circuit connectible through an on-off valve to a pipe to be examined and provided with an electromagnetic valve; a main conduit connecting the conduits of the first and second circuits to the compressed air source; a conduit of a third circuit communicating the conduits of the first and second circuits with each other; a calibration conduit branched off from one of the conduits of first and second circuits and connectible to a reference pipe through an on-off valve; an electromagnetic valve inserted in the conduit of the third circuit; a pressure transducer connected parallel with the electromagnetic valve of the third circuit C; and a detector adapted to produce a leak signal when the output signal of the pressure transducer exceeds a predetermined value; and a mechanism for sealing com

Abstract: An apparatus for pickling the inner wall of a tubular member, for example, a zirconium or zircaloy tubular member as a cladding tube for nuclear fuel. The apparatus features the use of ultrasonic instruments for measuring the inner diameter of the tubular member while pickling the inner wall of the same. Owing to the interlocked association of the instruments and mechanism for supplying a pickling liquid into the tubular member, the supply of the pickling liquid can be stopped as soon as the inner diameter has reached a predetermined value. Various mechanisms may also be incorporated in the apparatus to minimize the temperature variation along the length of the tubular member and to improve the accuracy of the measurement by the instruments.