A sensing system for sensing conditions or characteristics associated with
a process or thing. The sensing system includes one or more energy
converters and a sensor, which are coupled to the process or thing. A
node is coupled to the sensor and the energy-converter, and the node is
powered by output from the energy converter. In a more specific
embodiment, the node includes a controller that implements one or more
routines for selectively powering a wireless transmitter of the node
based on a predetermined condition. The predetermined condition may
specify that sensor output values are within a predetermined range or are
below or above a predetermined threshold. Alternatively, the
predetermined condition may specify that electrical energy output from
the energy converter is below a predetermined threshold. A remote
computer may be wirelessly connected to node and may include software
and/or hardware that is adapted to process information output by the
sensor and relayed to the computer via the node.