Please forgive me if this is posted somewhere and my searching / research has failed me. I’m looking to determine the typical wavelength at which the emitters in the QTR-8RC operate. The main reason I ask is because I’m curious whether these sensors will be able to detect through glass (for instance if you were to place a glass cover over them or had to detect a line beneath a very thin glass tabletop).
The reflectance sensor’s datasheet is available on the Resources tab of the product page for the QTR-8RC, and it specifies a peak emission wavelength of 940 nm. (As the note states, we actually use another similar sensor, but it has the same wavelength.)