Abstract: The disclosure relates to a method for determining and/or monitoring the state of a transformer oil, comprising the steps of a) performing an acoustic spectroscopy of the transformer oil, multiple ultrasonic emission signals of different frequencies and/or amplitudes being emitted into the transformer oil and corresponding reflected and/or transmitted ultrasonic reception signals of different frequencies and/or amplitudes being received after having passed through the transformer oil; and b) comparing the ultrasonic emission signals with the corresponding ultrasonic reception signals, an n-dimensional function characteristic of the transformer oil being ascertained; and c) matching the ascertained characteristic n-dimensional function from step b) with a reference function of corresponding dimension known for transformer oils, a reference transformer oil being determined; and d) registering a first value of at least one characteristic physical property of the transformer oil; and e) comparing the first val

Abstract: The disclosure relates to a method for determining and/or monitoring the breakdown voltage of a transformer oil, comprising the steps of a) performing an acoustic impedance measurement of the transformer oil, the impedance of a medium partially or entirely disposed in the transformer oil and capable of naturally vibrating and/or transmitting vibrations to the transformer oil is determined in at least one frequency band of defined frequency width; and b) calculating a resonator quality factor for the frequency band based on the determination performed in step a); and c) calculating an acoustic disbalance of the transformer oil based on the calculation performed in step b); and d) ascertaining the breakdown voltage of the transformer oil based on the calculation performed in step c). Furthermore, the disclosure relates to a device (100, 200) for determining and/or monitoring the breakdown voltage of a transformer oil.

Abstract: The disclosure relates to a method for determining and/or monitoring the breakdown voltage of a transformer oil, comprising the steps of a) performing an acoustic impedance measurement of the transformer oil, the impedance of a medium partially or entirely disposed in the transformer oil and capable of naturally vibrating and/or transmitting vibrations to the transformer oil is determined in at least one frequency band of defined frequency width; and b) calculating a resonator quality factor for the frequency band based on the determination performed in step a); and c) calculating an acoustic disbalance of the transformer oil based on the calculation performed in step b); and d) ascertaining the breakdown voltage of the transformer oil based on the calculation performed in step c). Furthermore, the disclosure relates to a device (100, 200) for determining and/or monitoring the breakdown voltage of a transformer oil.

Abstract: The disclosure relates to a method for determining and/or monitoring the state of a transformer oil, comprising the steps of a) performing an acoustic spectroscopy of the transformer oil, multiple ultrasonic emission signals of different frequencies and/or amplitudes being emitted into the transformer oil and corresponding reflected and/or transmitted ultrasonic reception signals of different frequencies and/or amplitudes being received after having passed through the transformer oil; and b) comparing the ultrasonic emission signals with the corresponding ultrasonic reception signals, an n-dimensional function characteristic of the transformer oil being ascertained; and c) matching the ascertained characteristic n-dimensional function from step b) with a reference function of corresponding dimension known for transformer oils, a reference transformer oil being determined; and d) registering a first value of at least one characteristic physical property of the transformer oil; and e) comparing the first val