| Comparison Item |
Infrared Through Beam Photoelectric Sensor |
Infrared Diffuse Reflective Photoelectric Sensor |
| Operating Principle |
The emitter and receiver are installed separately. The emitter continuously projects an infrared beam; when an object blocks the beam, the receiver signal is interrupted, indicating detection. |
The emitter and receiver are housed together. The emitted infrared light is reflected by the object’s surface and received by the sensor, indicating the presence of the object. |
| Structure Type |
Two separate units (emitter + receiver) |
Single integrated unit (emitter and receiver combined) |
| Detection Method |
Detects objects by beam interruption |
Detects objects by reflected light intensity |
| Sensing Distance |
Long |
Short |
| Anti-interference Capability |
Strong — resistant to ambient light, dust, and background interference |
Weak — easily influenced by ambient light, dust, or surface conditions |
| Installation Requirement |
Requires precise alignment between emitter and receiver |
Easy installation, single-side mounting only |
| Typical Applications |
Automatic doors, conveyor object counting, safety barriers, packaging and sorting systems |
Automatic soap dispensers, sensor trash cans, assembly positioning, presence detection |
| Advantages |
Long sensing range, high accuracy, strong anti-interference, reliable operation |
Simple installation, cost-effective |