Abstract: A device for reading and transmitting measured temperature values for a device for monitoring a fluid flowing inside a pipe is disclosed. The device may include a temperature sensor configured to provide temperature values in accordance with time and a processing module, as well as a transmitter connected to the temperature sensor and configured to transmit signals that represent said temperature values, and a receiver configured to receive said signals. The temperature sensor may be mounted in a position that is close to the pipe. In addition, the processing module may be configured to assess a temperature variation speed, and of producing a signal to alert of the transformation of the fluid to the solid phase, when the temperature variation speed decreases over a given time interval.