The Parallax QTI sensor uses a QRD1114 infrared (IR) reflective sensor to determine the reflectivity of the surface below it. When the QTI sensor is over a dark surface, the reflectivity is very low; when the QTI is over a light surface, the reflectivity is very high and will cause a different reading from the sensor.
• Phototransistor Output
• No contact surface sensing
• Unfocused for sensing diffused surfaces
• Compact Package
• Daylight filter on sensor