System (1) for measuring the temperature in a sterilisation autoclave comprising: at least one temperature transducer (3) positionable inside a sterilisation chamber (2) of the autoclave and at least one receiver (5) positionable outside the sterilisation chamber (2), wherein the receiver (5) comprises: a reception antenna (6), a receiving electronic circuit (16) connected to the reception antenna (6) and connectable with a process controller (8) of the autoclave, wherein said receiving electronic circuit (16) is configured to receive said digital temperature signal through the reception antenna (6), provide a control signal as a function of the digital temperature signal and transmit the control signal to the controller (8)； wherein the temperature transducer (3) comprises: a hermetically closable transducer housing (14)； a plurality of temperature probes (3a, 3b, 3c, 3d) adapted to generate an analog signal corresponding to the temperature to which they are exposed, said temperature probes (3a, 3b, 3c, 3d) being movable with respect to the transducer housing (14) and connected thereto through signal conductors for transmitting the analog temperature signal； a transmission antenna (4) connected to the housing of the transducer (14)； an electronic transduction circuit (10) housed inside the transducer housing (14) and connected to said signal conductors and to the transmission antenna (4), wherein the electronic transduction circuit (10) is configured to convert the analog temperature signal into a digital temperature signal and transmit it through the transmission antenna (4) to the receiver (5)； a primary battery (12) to allow an autonomous electric power supply of the electronic transduction circuit (10)； an activation device (11) configured to: switch on or off the transduction circuit (10) under determined conditions； pass from a reduced electricity consumption status to an active reception status of any signals coming from the antenna (4)； check if a valid sig
