About calibration:
1 If the collected temperature error exceeds 1%, it can be calibrated.
2 Calibration is not recommended if the error does not exceed 0.5%.
3. If the calibration causes a larger error, please short the RES jumper for 5 seconds to restore the factory settings, and then recalibrate.

How to calibrate the voltage value of PTDNC04:
The temperature value is in register 0x0000-0x0003 (0-3), and the calibration value is in register 0x0040-0x0043 (64-67)
It is recommended to calibrate the three temperature values ​​of high, medium and low at the same time. 
For example, -40-220℃ PT100 version: It is recommended to calibrate these three values: 10℃/100℃/200℃