Abstract: A boroscope sheath is disclosed for providing a boroscope with temperature protection during a boroscope inspection of a machine such as a gas turbine or a steam turbine. The boroscope sheath includes an elongate tube having a wall extending from a front end to a back end and around a central bore configured and arranged to allow removable insertion of a boroscope cooling channels extend in the wall. The boroscope sheath can be held in a first position relative to the machine when the machine is in use and moved to a second position relative to machine for inspection. Part of the boroscope sheath remain in the machine during use of the machine.

Abstract: A boroscope sheath is disclosed for providing a boroscope with temperature protection during a boroscope inspection of a machine such as a gas turbine or a steam turbine. The boroscope sheath includes an elongate tube having a wall extending from a front end to a back end and around a central bore configured and arranged to allow removable insertion of a boroscope cooling channels extend in the wall. The boroscope sheath can be held in a first position relative to the machine when the machine is in use and moved to a second position relative to machine for inspection. Part of the boroscope sheath remain in the machine during use of the machine.

Abstract: The invention relates to a method for detecting rubbing and/or contact points on machines with rotating parts. The rotating parts form an electrical coaxial system with respect to the stationary parts of such a machine, in which system electrical voltage pulses are propagated at a characteristic speed because of the small distance between the rotating and the stationary part. Short electrical voltage pulses and/or continuous alternating voltage signals are applied between the rotating part and the stationary part, an electrical connection occurring between the rotating and the stationary part at a rubbing and/or contact point. In order to locate this rubbing and/or contact point as a point of electrical discontinuity, the period of time until the reflected pulses arrive is measured along the path of propagation of the electrical voltage pulses and/or of the continuous alternating voltage signals.