Hi Erez,
The D A C sensor measures s i l i c o n temperature. This r u n s t y p i c a l l y 4 5 d e g C a b o v e r o o m a m b i e n t a i r t e m p .
U n d e r n o r m a l c o n d i t i o n s t h e D A C t e m p i s e x p e c t e d t o b e 6 5 d e g C o r b e l o w , h o w e v e r t h e s e n s o r h a s a + 3 / - 3 d e g C a c c u r a c y s o 6 8 d e g C c o u l d b e q u i t e n o r m a l .
I f t h e D A C is r e p o r ting 8 0 - 8 5 d e g C o r h i g h e r, I’d recommend c h e c king t h a t t h e r e i s n o t h i n g i m p e d i n g a i r f l o w i n a n d a r o u n d t h e u n i t , no direct source of heat, and that you are operating the desk within the specified ambient temperature limits.