Sensor assembly and method for sensing status condition of electrical equipment

Sensor assembly for sensing a status condition of a liquid-filled electrical equipment, the sensor assembly comprising:

• a light source;
• a first hydrogen detection section, the first hydrogen detection section being optically coupled to the light source for receiving light from the light source, wherein the first hydrogen detection section has a first hydrogen sensitive layer that changes an optical response with respect to received light depending on whether an amount of hydrogen at the first hydrogen sensitive layer is above or below a first threshold;
• and
• a first output section optically coupled to the first hydrogen detection section for receiving light having interacted with the first hydrogen sensitive layer such that received light depends on the optical response of the first hydrogen sensitive layer, the first output section being configured for outputting an output signal as a low-hydrogen output signal when the optical response corresponds to an amount of hydrogen below the first threshold, and as a high-hydrogen output signal, different from the low-hydrogen output signal, when the optical response corresponds to an amount of hydrogen above the first threshold, wherein the optical response is at least one of a reflection and a transmission of the first hydrogen sensitive layer.