In the absolute max rating section of the AD595 datasheet, you quote the
temp range as being -55 to +125. However, in the second sentence of the fifth
paragraph of the Product Description on Page 1 of the datasheet you state 'Both
are designed to be used from 0 degrees to 50 degrees'. Can you explain the
difference in these two temperature ranges please?
If you take a look at page 2 on the AD595 datasheet you will see the AD595
specified ambient operating temperature range for temperature measurement is 0°
C to +50°C. In the absolute maximum ratings the operating temperature range
(unspecified) is -55°C to +125°C.
To meet the specifications in the datasheet, the device ambient temperature
should be inside the datasheet specified range of 0°C to +50°C. Operation at
ambient temperatures outside this range will result in additional errors. Table
II in the application note AN-369 shows the maximum calculated
errors at various ambient temperatures across the full operating range from -55°
C to +125°C.
I recommend you read the application note AN-369 as this should
clarify the situation.