A method for sensing pulsations in a process device (16;200) coupled to an industrial process of the type used in monitoring a process variable of industrial process, the method comprising: sensing a process variable with a process variable sensor; providing a process variable output based upon the sensed process variable; physically coupling a piezoelectric transducer to the industrial process; receiving pressure pulsations from the industrial process through the physical coupling; coupling the pressure pulsations to the piezoelectric transducer and providing an electrical output from the piezoelectric transducer in response to the pressure pulsations; providing the electrical output to electrical circuitry of the process device (16; 200), thereby providing power to the electrical circuitry; and using the electrical circuitry to diagnose operation of the industrial process based upon the electrical output; and characterised by: causing the piezoelectric transducer to receive a control signal which causes movement of the piezoelectric transducer to induce pressure pulsations in a process fluid; and sensing the induced pressure pulsations with the process variable sensor, and using the electrical circuitry to diagnose transmitter (16; 200) operation based upon the sensed pressure pulsations. sensing a process variable with a process variable sensor; providing a process variable output based upon the sensed process variable; physically coupling a piezoelectric transducer to the industrial process; receiving pressure pulsations from the industrial process through the physical coupling; coupling the pressure pulsations to the piezoelectric transducer and providing an electrical output from the piezoelectric transducer in response to the pressure pulsations; providing the electrical output to electrical circuitry of the process device (16; 200), thereby providing power to the electrical circuitry; and using the electrical circuitry to diagnose operation of the industrial process based upon the electrical output; and characterised by: causing the piezoelectric transducer to receive a control signal which causes movement of the piezoelectric transducer to induce pressure pulsations in a process fluid; and sensing the induced pressure pulsations with the process variable sensor, and using the electrical circuitry to diagnose transmitter (16; 200) operation based upon the sensed pressure pulsations. providing the electrical output to electrical circuitry of the process device (16; 200), thereby providing power to the electrical circuitry; and using the electrical circuitry to diagnose operation of the industrial process based upon the electrical output; and characterised by: causing the piezoelectric transducer to receive a control signal which causes movement of the piezoelectric transducer to induce pressure pulsations in a process fluid; and sensing the induced pressure pulsations with the process variable sensor, and using the electrical circuitry to diagnose transmitter (16; 200) operation based upon the sensed pressure pulsations. causing the piezoelectric transducer to receive a control signal which causes movement of the piezoelectric transducer to induce pressure pulsations in a process fluid; and sensing the induced pressure pulsations with the process variable sensor, and using the electrical circuitry to diagnose transmitter (16; 200) operation based upon the sensed pressure pulsations.