DG408 into resistor divider into MCP3201.
and to solve the Granularity issues a variable Vref (DAC) might be used to solve this:
voltage divider going from 5 to 15 V down to 0 to 5 V means there will be roughly
three times less1/3 less usable information detectable in the output signal
so change the Vref as required to increase the effective available information by providing a Vref suitable to the measurements.
Bob