Photoelectric Sensors Are Classified According To Detection Methods

1. Diffuse reflective photoelectric sensor

The diffuse reflection photoelectric sensor is a sensor integrating the transmitter and the receiver. When the detected target object passes through the light detection area, a sufficient amount of light emitted by the photoelectric sensor emitter is reflected back and detected by the receiver, so that the photoelectric The sensor outputs an on/off signal. A diffuse reflective photoelectric switch is the preferred detection mode when the surface of the object to be inspected is bright or its reflectance is high. The object to be inspected is not limited to metal.

Feature: The effective detection distance is determined by the light reflectivity of the target object, and is determined by the surface properties and color of the target. The background is used to adjust the measured distance, sensitive to dust on the target and sensitive to the target's change. It also has the function of preventing mutual interference and is easy to install.

2. Retroreflective photoelectric sensor

Retroreflective type is also called lens (surface) reflective photoelectric sensor. Retroreflective sensor is also a combination of transmitter and receiver. The light emitted by the sensor emitter passes through the mirror and is reflected back to the receiver. When the light is completely blocked, the photoelectric sensor generates a switching signal corresponding to the light change.

Features: Suitable for discriminating opaque objects; applying the high reflectivity of the mirror, it is easy to achieve longer detection distance, and it is more resistant to ambient light interference, and is more suitable for outdoor or dusty environments. It also has the function of preventing mutual interference and is easy to install.

3. On-beam photoelectric switch

The through-beam photoelectric sensors are structurally independent of each other and consist of a transmitter and a receiver optical axis mounted opposite each other. Light from the transmitter enters the receiver directly through the area under test. When the detected object passes through the area between the transmitter and the receiver and blocks the light, the photosensor outputs a switching signal. The on-beam photoelectric sensor is the most reliable detection mode when the detected object is opaque.

Features: Effective detection distance is longer, it is very suitable for distinguishing opaque reflective objects. Not easily affected by ambient light, more reliable in outdoor or dusty environments. However, both units need to be separately wired, and the overall consumption current of the sensor is relatively higher.