IR sensor: just one question.

I'm asking if theese kind of common sensors based on TCRT5000 have an output that is digital or analog:

If not, can you post some tiny IR sensor wic i've to use for measuring IR reflectance of surfaces.

The top one is analog, (has a sensitivity pot), the lower is digital (has an inverting schmidt trigger) for digital (flip / flop) output.

Do you want to get the relative reflectivity of different surfaces? Then the digital one for sure doesn't work (it only tells you whether there's a surface) and the analog one may or may not work.

The hardest part for such a measurement is to line up the two sensors and the surface you try to measure perfectly.