This sensor was designed to measure at very low temperatures and with a big thermal range.
The original calibration round 3% os accuracy, but if you need improve you can perform a calibration.
The calibration is based on 3 parameters. 1. Internal Voltage, 2. Offset, 3. Gain
1. Internal Voltage. After adjust this value, the device will be periodically and automatically calibrated. Normally this step was made in factor so you dont need touch it.
2. Offser, is a fixed value that will be applied in same way to all measurement range. This value will be adjusted at ambient temperature for a acurate measure.
3. Gain. Sometimes at ambient temperature the read are right, but at end of scale have a small difference. This will be corrected changng the gain.
This say that full calibration will made adjusting 2 parameters, one at ambient temperature ( offset ), and the another at very cold temperature ( gain ).