By Placing your finger between the infrared led and the phototransistor of the sensor, your heartbeat dilates the blood vessels in your finger, which will filter the IR creating a pulsating signal.
It is important is to keep stray light off the photo-transistor as this will add considerable noise to the results.
- Voltage : 3v to 5v
- 5mm Infrared emitter
- Pin pitch : 2.54mm
- Size: 19mm x 15.5mm