A sensor comprises a sensor layer comprising a ceramic material; an adhesion layer comprising chromium, the adhesion layer adhered to one or more portions of a liquid facing surface of the sensor layer; and an isolator film comprising a polymer, the isolator film overlaying a liquid facing surface of the adhesion layer. The isolator film may be used to protect the sensor from corrosive and high temperature fluids, for example to protect the sensor from long term exposure to hot water between 85° C. and 100° C.