ITEM NAME:KY-039 Finger Measuring Heartbeat Sensor Module for ArduinoTT.The most important is to keep the shield stray light into the phototransistor. 1x heartbeat Sensor Module. Pulse monitor works as follows: The LED is the light side of the finger, and phototransistor on the other side of the finger, phototransistor used to obtain the flux emitted, when the blood pressure pulse by the finger when the resistance of the phototransistor will be slight changed.
