PF21R series photoelectric sensors are retro-reflective photo sensors / photocell witches with smaller and clearer light spot that is visible laser-like LED light and high enclosure rate of IP67. The universal optical sensors are widely used for object detection, presence detection and position detection. The PF21 series photo sensors are widely applied to industrial automation fields.

PF21 series Mini-type Photoelectric Sensor is one new and upgraded product. It includes through beam type, polarized reflective type and diffused type.
The compact design ensures the application and installation at limited space, The detection distance of opposed type is up to 15m, Polarized sensor with high anti-interference performance, The diffused type photocell sensor with background suppression function can detect  the reflective surface object accurately.
The PF21 series reflection type photoelectric sensors are widely applied to different business fields such as automatic doors, warehousing and logistics, intelligent parking, access gates and other scenarios.

Main Features

PF21R Photoelectric Sensor Features:

1. Polarization function, anti-interference strong

2. Laser-like pinpoint-LED light source technology, brighter and more accurate light point

3. Resistant to ambient light, no crosstalk problem

4. Compact size, easy to install

5. Metal threaded mounting holes for stable installation

PF21B Photoelectric Sensor Features:

1. Diffuse reflection sensor with background suppression

2. Laser-like pinpoint-LED light source technology for brighter and more precise light points

3. High light immunity, no crosstalk problems

4. Extreme blind spot technology

5. Compact size, easy to install

6. Metal threaded mounting holes for secure installation

PF21T Photoelectric Sensor Features:

1. Visible red and infrared light sources available

2. Compact size, easy to install

3. Detecting distance 5m/10m/30m optional

4. Metal threaded mounting holes for stable installation

Principle and application of photoelectric sensor

A photoelectric sensor (photocell switch)is used to detect the presence (or absence) of an object, or for measuring the distance between a point and an object. It uses visible red light or infrared light from a transmitter and also has a photoelectric receiver. A photoelectric sensor becomes a popular choice in automation since they provide quick and reliable results without having to physically touch the object.
Types of Photoelectric Sensors.

Photoelectric sensors come in different housing styles, sizes, and different working styles. There are three main types of photoelectric sensors:

1. Diffuse type photoelectric sensors
A light beam is transmitted in the direction of the object in question. The light is reflected from the object which is received by the receiver of the sensor confirming the presence of the object. The amount of light received is used by the sensor to measure the distance to the object.
2. Through-beam type photoelectric sensors
A light beam is transmitted from the transmitter on to a receiver while the object of interest is placed between the two. The object interrupts the light and changes the amount of light that falls on the receiver. This is used for sensing the object.
3. Retro-reflective type photoelectric sensors
A light beam from the transmitter falls on to a reflector. The reflector reflects back the light on to the receiver. The object of interest falls between the transmitter and the reflector and interrupts the light beam.

Depending on the requirement, the photoelectric sensor is selected. More sophisticated sensors that are aimed at higher accuracy come with the ability to suppress the background making it possible for them to precisely detect objects.   Applications of Photoelectric Sensors across various Industries.