Does the TMP117 have a known dependence of its reading on pressure? I appear to be measuring something of order 0.01 C/mbar
In my case, the TMP117 sensor together with some other components on the following board:
https://www.adafruit.com/product/4821
So I can't be sure its the TMP117 but thought I'd check to see if this is a known source of uncertainty.