What are the uses of dual sensor temperature sensors?

Differential Temperature Measurement

Measure and output the difference between two process temperatures

Average Temperature measurement

Measure and output the average of process temperatures

Redundant temperature measurement

Device switches to backup sensor upon failure of primary server

Dual Range Switching / Split range measurement

Make use of the best possible accuracies of two different sensor within the single measurement range to improve the accuracy throughout the range

Sensor Drift Alert

Alert the user about drift in the sensor by monitoring the difference between sensor 1 and sensor 2 against a preset delta value.