Abstract: A method for determining the location of a leak in pressure-carrying vessels, including a plurality of probes spaced-apart on walls of the vessels for picking up high-frequency solid-conducted sound noises, and an amplifier connected to the probes, includes forming an r.m.s. value in the amplifier from the sound noises, comparing the r.m.s. value with a threshold value, issuing a signal if the r.m.s. value exceeds the threshold value, comparing the solid-conducted sound noises from at least two probes with each other for localizing the leak, placing the r.m.s. values of the solid-conducted sound noises in a relationship relative to the spacing between the probes based on the comparison, and determining the location of the leak as the location of the maximum solid-conducted sound noise from the relationship.

Abstract: Method of acoustic-emission testing of a steel component such as a vessel of pipeline especially of primary circulatory loops of nuclear reactor installations wherein the component, on one hand is subjected to a pressure medium, such as water, and, on the other hand, to ultrasonic pulses emitted during deformation development resulting from growth of cracks therein or from leaks and transmitted through the component, which includes detecting and amplifying the ultrasonic pulses with equipment, respectively, formed of test probes, which are disposed so as to determine respective sources of acoustic emission due to differences in transmission time of the ultrasonic pulses through the component, and of electronic amplifiers operatively associated with the test probes, and then feeding a resultant amplified defect signal from the equipment to a display, the equipment being tuned to reception of a frequency band of acoustic-emission spectrum which is above a limiting frequency f.sub.

Abstract: Method of monitoring equipment wherein a measured value signal in the form of an electrical a-c signal is fed to the measuring channel of an electric circuit and a mean value output signal is formed by the electronic circuit in accordance with the amplitude of the measured value signal, which includes setting an amplitude limit as a function of the mean value signal and the amplitudes of the measured value signal, automatically adapting the amplitude limit with a predetermined time constant to changes in the mean value signal, setting a limit of a number of occurrences when the amplitudes of the measured value signal exceed the amplitude limit, and activating an alarm if the occurrence limit is surpassed within a settable time period, and system for carrying out the method.