I have a common PIR occupancy sensor (Lutron MS-OPS5M-WH). I am trying to get the sensor to cover an irregular-shaped room.
I could expand the field-of-view of the sensor to cover the whole room by installing a mirror so that the PIR sensor could "see" around a small corner. However, I need to know what material to make the mirror out of. I think standard soda-lime glass would reflect long-wave infrared, whether or not it's silvered, but it depends on the spectrum of light that these PIR sensor use.
Is this concept of using a mirror surface to let a PIR sensor see around corners a valid idea? And if so, what material does the mirror need to be made of?