Why do I keep getting negative CPU temperature readings?

pi@orangepizero:~/klipper_config/config$ armbianmonitor -m
Running unprivileged. CPU frequency will not be displayed.
Stop monitoring using [ctrl]-[c]
Time        CPU    load %cpu %sys %usr %nice %io %irq   CPU  C.St.

21:01:44:   ---      0.18   4%   1%   2%   0%   0%   0% -3280°C  0/4
21:01:49:   ---      0.17   2%   0%   1%   0%   0%   0% -2433°C  0/4
21:01:54:   ---      0.15   2%   0%   1%   0%   0%   0% -2675°C  0/4
21:02:00:   ---      0.14   4%   1%   2%   0%   0%   0% -2796°C  0/4
21:02:05:   ---      0.13   2%   0%   1%   0%   0%   0% -2312°C  0/4
21:02:10:   ---      0.12   3%   1%   2%   0%   0%   0% -3038°C  0/4
21:02:15:   ---      0.19   5%   1%   3%   0%   0%   0% -2796°C  0/4
21:02:20:   ---      0.17   2%   1%   1%   0%   0%   0% -2312°C  0/4
21:02:25:   ---      0.16   2%   0%   1%   0%   0%   0% -3038°C  0/4
21:02:31:   ---      0.15   4%   1%   2%   0%   0%   0% -1706°C  0/4
21:02:36:   ---      0.13   2%   1%   1%   0%   0%   0% -3038°C  0/4
21:02:41:   ---      0.12   2%   1%   1%   0%   0%   0% -2554°C  0/4
21:02:46:   ---      0.11   4%   1%   2%   0%   0%   0% -3402°C  0/4

 

Do you have opi zero or opi PC?