Development of Graphene Oxide‐Based Sensor with an Aspect for Moisture Sensing in Transformer Oil

Graphene oxide (GO)‐based humidity sensors are appealing because of their interesting physicochemical properties. This research focuses on developing a novel GO‐based relative humidity (%RH) sensor for detecting moisture in transformer oil. GO is derived from the modified Hummers method using graphite as a precursor. The sensor fabrication includes depositing the GO layer on a substrate by drop‐casting. The effects of vital parameters on sensor performance at different frequencies (100 Hz–100 kHz) for various %RH (10–90 %) are studied. The short‐term stability of the capacitive response of the proposed sensor, showing a maximum deviation of 6.7 %, was found. An experimental setup simulated the environment of an oil‐filled transformer to test the developed sensor inside the laboratory which can measure the moisture in transformer oil at different temperatures to prevent liquid insulation failure, ensuring longer life.