Place it in a resistor bridge with 3 equal value resistors, add a trimmer potentiometer to give a small amount
of adjustment of one ot the resistors. Now just add a low-input-offset comparator between the
arms of the bridge to detect which has the higher voltage.
Some extra amplification of the voltage difference might be a good idea though, strain gauges
vary by a few tenths of a percent typically...
Have you measured the resistance of the sensor?