Dealing with zero offsets signals tackled in this app note from Murata. Link here (PDF)
Many transducer outputs exhibit a dc offset voltage when the output level would normally be expected to be zero Volts (corresponding to a display reading of “000”). As an example, consider a pressure transducer whose output levels of 1.0Vdc to 6.0Vdc are required to produce display readings of “000” to “400” respectively. To obtain the desired readings, the 1-6V signal has to be attenuated fi rst, and then its 1V offset voltage must be subtracted or nulled to zero.