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 . <EOS>