Specifications : 
Using infrared reflective sensor TCRT5000
The detection distance: 1mm ~ 8mm apply focal distance of 2.5mm
The comparator output signal clean, good waveform, driving ability, more than 15mA
With a multi-turn precision potentiometer adjustable sensitivity adjustment
The working voltage of 3.3V ~ 5V
The output format: digital switching outputs (0 and 1)
A fixed bolt holes for easy installation
A small PCB board size: 3.2 x 1.4cm
Using a wide voltage LM393 comparator
Usage:
Meter pulse data sampling,Fax paper shredders detection,Obstacle detection, Black and white line detection
Module functions
TCRT5000 sensor of infrared emission diode constantly launch infrared, the infrared ray is emitted when the intensity of reflected back has not been reflected or but is not big enough, the light activated triode has been in the off state, the output end of the module at this time for the high level, indicating diode has been put out state; Detected objects appear within the scope of testing, infrared light is reflected back and strength is enough big, light activated triode saturation, at this time the output of the module for the low level, instructs the diode lights.