parece que wikipedia arroja algo de información relevante.
Magnetostriction
Magnetic flux in a ferromagnetic material, such as the core, causes it to physically expand and contract slightly with each cycle of the magnetic field, an effect known as magnetostriction. This produces the buzzing sound commonly associated with transformers[31] that can cause losses due to frictional heating. This buzzing is particularly familiar from low-frequency (50 Hz or 60 Hz) mains hum, and high-frequency (15,734 Hz (NTSC) or 15,625 Hz (PAL)) CRT noise.
de todas formas, ningún otro sensor CT produce tal ruido, por lo tanto, es peligroso? como puedo valorar si es demasiado ruido? es decir, que algo va mal?
gracias