A temperature sensor for measuring a temperature of a mixture being mixed in an internal mixer, the temperature sensor comprising: a fixed part in the form of a substantially cylindrical body with a predetermined length extending between a measuring end, where the temperature of the mixture is measured by the sensor, and an access end, and with a conduit delimited inside the body incorporating a face towards the measuring end, the conduit having a length substantially equal to the predefined length of the body; a removable part arranged inside the conduit of the body towards the measuring end where it abuts the face, the removable part with a predetermined length extending between a clamping end, where the removable part is clamped with respect to the fixed part, and a contact end, where the removable part comes into contact with the mixture, the removable part with a shoulder defined at the clamping end that engages the face of the body, and the removable part with a conduit of a predetermined length within the removable part that is defined by the distance between the shoulder and the opposite contact end, the removable part incorporating a temperature measuring element or elements arranged inside the conduit of the removable part at the contact end; and a blowing stem in communication with a source of compressed air that extends along the conduit of the body from the access end, where the blowing stem enters the body, and terminates at an outlet end arranged in the conduit of the removable part, so that the compressed air exits the blowing stem and passes uninterruptedly by the temperature measuring element or elements at the contact end. a fixed part in the form of a substantially cylindrical body with a predetermined length extending between a measuring end, where the temperature of the mixture is measured by the sensor, and an access end, and with a conduit delimited inside the body incorporating a face towards the measuring end, the conduit having a length substantially equal to the predefined length of the body; a removable part arranged inside the conduit of the body towards the measuring end where it abuts the face, the removable part with a predetermined length extending between a clamping end, where the removable part is clamped with respect to the fixed part, and a contact end, where the removable part comes into contact with the mixture, the removable part with a shoulder defined at the clamping end that engages the face of the body, and the removable part with a conduit of a predetermined length within the removable part that is defined by the distance between the shoulder and the opposite contact end, the removable part incorporating a temperature measuring element or elements arranged inside the conduit of the removable part at the contact end; and a blowing stem in communication with a source of compressed air that extends along the conduit of the body from the access end, where the blowing stem enters the body, and terminates at an outlet end arranged in the conduit of the removable part, so that the compressed air exits the blowing stem and passes uninterruptedly by the temperature measuring element or elements at the contact end.