Does the Sentrius RS191 have a calibration certificate?

The temperature sensor inside the Sentrius RS191 is the same as the Sentrius RS186 – so the information is the same for both SKUs.

The Integrated temp/RH sensor inside the Sentrius RS191 is based on the SiLabs Si7021-A20 integrated. Each SiLabs sensor is calibrated under controlled conditions which are traceable via accredited labs to standards set by NIST, the certificate of calibration from SiLabs can be found here; https://www.silabs.com/documents/public/miscellaneous/si70xx-calibration-certificate.pdf

The SiLabs part has a drift spec of <0.05C/year typical, as stated in the data sheet which can be found here; https://www.silabs.com/documents/public/data-sheets/Si7021-A20.pdf