Just to add this to this thread for future reference for others looking for an outdoor solution (that likely won't last forever but at the price of these Iris Motions it's not a show stopper).
2" PVC pipe with bell end which is just oversized enough to accommodate the sensor. Push the sensor forward, cap the bell end, cover the open end with something to reduce exposure (Plexiglas won't work for weatherproofing as it filters and/or reflects the IR). I am still working on a better bug/dust/rain screen. Ideas Welcome.
This 7" pipe limits the region viewed to about 5' at 12-15' away. Avoid pointing towards the sun and "sun soaking" materials like a brick wall.
Concept still being tested ...but for less than $20 I've got an easily concealed motion sensor at a remote gate. Oh, and temp & humidity as a bonus (cause it isn't sealed).
