THERMOMETER HAVING A DIAGNOSTIC FUNCTION

A device for determining the temperature of a medium includes a temperature sensor with a resistance element placed in electrical contact using first and second connection lines, wherein the first connection line is divided into a first section and a second section. The first section faces the sensor element and is composed of a first material, and the second section faces away from the sensor element and is composed of a second material which differs from the first material. The second connection line is composed of the second material. The first section of the first connection line and at least one part of the second connection line form a first difference temperature sensor in the form of a thermocouple. The first and second connection lines are attached to the resistance element so that the first difference temperature sensor detects a temperature gradient at the location of the temperature sensor.