Heat exchanger plate and a plate heat exchanger with insulated sensor internal to heat exchange area

A double wall heat exchanger plate, comprising

• a heat transfer area, and
• an edge area, which extends around and outside the heat transfer area,
• wherein the double wall heat exchanger plate is formed by two adjoining plates compressed to be in contact with each other,
• wherein the double wall heat exchanger plate comprises a sensor which is located in the heat transfer area and is configured to sense at least one parameter and to produce a signal depending on the parameter and that the sensor comprises a sensor probe that is provided between the adjoining plates of the double wall heat exchanger plate, said parameter comprising the capacitance,
• wherein the double wall heat exchanger plate is configured to be included in a plate heat exchanger having a plurality of the double wall heat exchanger plates being arranged beside each other to define a plurality of first plate interspaces for a first medium and a plurality of second plate interspaces for a second medium,
• wherein the sensor comprises an insulation which insulates the sensor probe from electric contact with the adjoining plates, and
• wherein the sensor is configured to be disposed in one of the first or second interspaces.