Typically, the strain guage output would be fed to an op-amp with an offset of 2.5V, so that the range of values being measured still fell between 0 and 5V, with 2.5V being the relaxed condition, and lower voltages representing compression and higher values representing tension (or the other way around).
so i can offset the voltage to 2.5V withouht the opamp and still get it as an aref? is that the correct way of understanding?