The invention provides apparatus having a sensor system for providing sensor information for a monitoring, control or other operating function of the apparatus. The sensor system comprises: a transducer (16) adapted to be responsive to a predetermined environmental characteristic of the apparatus for providing an electrical output, and means (18) adjacent to the transducer to accentuate the said characteristic. At least one sensor (20) is arranged to be operated by power derived from the electrical output for generating a detection signal, and means (38, 40) arranged to be operated by power derived from the electrical output and responsive to the detection signal are also provided for communicating sensor information to a processing unit remote from the sensor system and associated with the said function.