invention as well as the best mode of practicing same and is not intended to limit the invention to the specific embodiment illustrated embodiments of the invention incorporate a strain gauge as a transducer to sense the presence of a fluid either through displacement buoyancy of a structure or by fluid pressure deforming a strain gauge platform such embodiments can be implemented as solid state structures which can be digitally calibrated for various settings or pressure in one aspect of the invention such transducers can be coupled to electronic control and switching circuitry which can switch electrical energy to activate a load such as an electric motor for a pump advantageously motor starting inrush currents are diverted away from the transducers in such embodiments further such transducers can accurately respond to changing conditions such as level or pressure resist vibration and can withstand harsh operating environments the control and switching circuitry can include relatively high power semiconductor switches which are controlled by one or more programmable processors which in turn are coupled to one or more solid state transducers preferable strain gauges the processor s can digitally calibrate one or more strain gauges in another aspect of the invention a solid state switch such as a triac can be coupled in parallel with a relay to a pump motor connector the switch and relay can be independently controlled by control circuits in the unit in response to signals from the strain gauge the control circuits can bias the switch to a low impedance state to couple electrical energy to the pump connector in this state the switch can couple the motor start up inrush current.