First of all, this setup will not allow you to get a range of 0÷5V at the ADC input. Simply because the LM324 cannot swing up to its positive rail. It will also introduce potential offset voltages that will most certainly be able to ruin a 10 to 50mV measurement. 

I suggest getting an instrumentation amplifier or a selectable gain amplifier such as the MCP6G01. With a selectable gain from 1 to 100 you'll be able to maintain some accuracy within 2 orders of magnitude (e.g. from 0.1 to 10 Ohms).

Measuring Resistance of a Wire With an ADC
Is decoherence even possible in anti de Sitter space? The spatial conformal boundary acts as a repulsive wall, thus turning anti de Sitter space into an eternally closed quantum system. Superpositions remain superpositions and can never decohere. A closed system eventually thermalizes and undergoes Poincare recurrences. Whatever the dual is to an interacting conformal field theory, is it really a theory of quantum gravity, or does it only look like one superficially?
