As far as observium documentation says, Papouch environmental sensors are supported. Therefore, (because I don't trust this obsolete leftover code from one of my predecessors) I've decided to get upstream version first, and then maybe apply some changes.
Sadly enough, I am not able to get this working. I've moved ancient code to some backup files, and refetched them from SVN, but I still can't see temperature graph on my papouch devices.
# svn status -u
? muj.patch
? html/images/login.png-orig
? html/includes/jpgraph
? html/includes/navbar-custom.inc.php-old
M 9675 includes/defaults.inc.php
? includes/definitions/os.inc.php-new
? includes/definitions/os.inc.php-pre20190118
? includes/definitions/os.inc.php-work
? includes/definitions/rrdtypes.inc.php-pre20190118
? includes/discovery/os/papouch.inc.php-pre20190118
A + - includes/discovery/sensors/papouch-smi.inc.php
? includes/discovery/sensors/papouch-smi.inc.php-pre20190118
Status against revision: 9675
# svn diff includes/discovery/sensors/papouch-smi.inc.php
#
That because you use stable branch, all changes by first going to rolling (trunk).
Wait for next stable update or switch to trunk.