SMD IR Sensor ITR8307

Description of SMD IR Sensor ITR8307 The ITR8307 consist of an infrared emitting diode and an NPN silicon phototransistor, encased side-by-side on converging optical axis in a black thermoplastic housing The phototransistor receives radiation from the IR only .This is the normal situation. But when an object is in  between, phototransistor could not receive the radiation.