You can use a couple of different options here.
The ADC11 11-channel data logger or the ADC24 16-channel data logger.
Both units have multiple inputs but differ as follows:
The ADC11 has an input range of 0-2.5v, the ADC24 has many ranges but the max is Â±2500mV. Both devices would require a potential divider to bring the voltage into range and the ADC11 would require a DC offset to allow for the -12v expected.
Further information can be found here: