linearize
I agree that with only 2 decades, it should be easy to linearize by software. You will lose some resolution at one end of the curve. So probably the AD convertor will have to be of a higher resolution. If the sensor is resistive, then it would be better to use a resistance to pulse-width or resistance to frequency conversion as it gives a much higher resolution. For example, with thermistors, It have found using a simple monostable to be the easiest way to acquire non-linear data and then linearize in software. For some humidity sensors, however the scheme does not work due to the AC excitation requirements.