Pololu QTR-1A Reflectance Sensor – Analog IR Line Sensor (2 Pack)

The Pololu QTR-1A Reflectance Sensor is a compact infrared reflectance module designed for line detection, edge sensing, and short-range proximity measurement. It integrates an IR LED and phototransistor that produce an analog voltage proportional to reflected light intensity. Operating at 5 V with a typical current consumption of 17 mA, the sensor delivers reliable readings for high-contrast surface detection. Its small 12.7 × 7.6 mm footprint allows installation in dense arrays, making it suitable for robotics, automation, and embedded sensing applications.

• Infrared LED and phototransistor reflectance sensing pair
  
• Analog voltage output proportional to reflected IR light
  
• 5 V operating voltage compatible with microcontrollers
  
• Typical current consumption around 17 mA
  
• High sensitivity for line detection and contrast sensing
  
• Optimal sensing distance around 3 mm
  
• Maximum recommended detection distance up to 6 mm
  
• Compact 12.7 × 7.6 mm PCB for dense sensor arrays
  
• Integrated current-limiting resistor for safe LED operation
• Suitable for line follower and edge detection robots
  
• Direct interface with analog inputs on Arduino boards
  
• Supplied as 2 sensors per package

• Operating Voltage: 5V DC
• Typical Current Consumption: 17mA
  
• Output Type: Analog Voltage Output
  
• Output Voltage Range: 0V to Supply Voltage
  
• Optimal Sensing Distance: 3mm
  
• Maximum Recommended Distance: 6mm
  
• IR Emitter Type: Infrared LED
  
• Receiver Type: Phototransistor with Pull-up Resistor
  
• PCB Dimensions: 12.7mm × 7.6mm × 2.5mm
  
• Mounting Orientation: Parallel to sensing surface
  
• Interface Type: Analog Input (ADC)
  
• Sensor Weight: 0.2g per sensor
  
• Pack Quantity: 2 Sensors
  

• Pololu QTR Reflectance Sensor Application Note (pdf)
• Datasheet of Fairchild's QRE1113GR sensor (pdf)
• 3D model from grabcad.com
• Pololu AVR library
• Arduino library

• Pololu QTR-1A Reflectance Sensor Tutorial
• Sensor Qtr1a-Pololu