Fork Sensors, the Best Choice for Range, Reliability, Ease of Installation

Photoelectric sensors are a staple within many industries when it comes to automation thanks to their non-contact detection over longer ranges than many other sensing types. Also available in a variety of housing types and protection classes to meet the specific demands of an application, they offer manufacturers many different variants and models. The range of styles can make selecting the perfect photoelectric sensor for your specific application challenging. This post highlights the benefits of through-beam sensors and why fork sensors specifically, are often the ideal sensor for the job.

Through-beam sensors can detect anything, regardless of color, texture or reflectivity. This makes them highly efficient in any application where material or parts need to be detected during the process. They require an emitter and receiver. The emitter sends a light beam toward the receiver. When this light beam is blocked, the sensor will trigger. A common example of this is the sensor system on a garage door that detects obstructions and keeps the door from closing. (The software can also inverse this, so the sensor triggers when the light beam is not obstructed. Read more about these light-on/dark-on modes).

Traditional Through-Beams vs. Fork Sensors

Through-beam photoelectric sensors are simple technology that are non-contact, reliable and can operate over distances up to 100 meters, making them a go-to for many applications. But they aren’t without fault. Because the emitter and receiver are typically in separate housings, the two parts must line up perfectly to work. This alignment takes extra time during assembly and is prone to problems in the future if the emitter or receiver move,  even slightly. Machine vibrations can cause a misalignment.

Fork sensors, also called C slot or U slot sensors, incorporate both the emitter and the receiver into a single body, providing the benefits of a through-beam sensor without the installation issues.

This allows for reduced installation and maintenance time of the sensor in several ways:

    • Mounting a single sensor instead of two
    • Half as many cables needed for networking
    • No touchy alignment needed when installing the sensor
    • No maintenance needed re-aligning the sensors in the future

Photoelectric fork sensors come with sensing windows widths up to 220 mm and a range of light sources to accommodate many application needs. Check them out the next time you are considering a photoelectric sensor and see if they’re the best choice for your application.

Photoelectric Sensors in the Packaging, Food, and Beverage Industry

The PFB industry requires the highest standards of quality and productivity when it comes to both their products and their equipment. In order to keep up with the rising demands to produce high quality parts quickly, many in the industry have incorporated photoelectric sensors into their lines. With their durable designs, accurate measurements and fast data output speeds, it is easy to see why. Combine the sensors’ benefits with the clean and well-lit environment of a PFB plant, and it begins to feel like this product was made specifically for the industry. There are many variants of photoelectric sensors, but the main categories are: through beam, diffuse, and retro-reflective sensors.

Through Beam

Through beam sensors come in many different shapes and sizes but the core idea stays the same. An emitter shoots LED red, red laser, infrared, or LED infrared light across an open area toward a receiver. If the receiver detects the light, the sensor determines nothing is present. If the light is not detected, this means an object has obstructed the light.

Applications:

  • Object detection during production
  • Detecting liquid in transparent bottles
  • Detecting, counting, and packaging tablets

Diffuse Beam

Diffuse beam sensors operate a little differently in that the emitter and receiver are in the same housing, often very closely to one another. With this sensor, the light beam is emitted out, the light bounces off a surface, and the light returns to the receiver. The major takeaway with the diffuse beam sensor is that the object being detected is also being used as the reflecting surface.

Applications:

  • Label detection
  • Monitoring the diameter of film
  • Verifying stack height on pallet

Retro-Reflective Beam

Retro-reflective sensors are similar to diffuse beam sensors in that the emitter and receiver are also contained within the same housing. But this sensor requires an additional component — a reflector. This sensor doesn’t use the object itself to reflect the light but instead uses a specified reflector that polarizes the light, eliminating the potential for false positive readings. Retro-reflective sensors are a strong alternative to through beam when there isn’t room for two separate sensor heads.

Applications:

  • Transparent film detection
  • Detection of shrink-wrapped pallets
  • Detecting any reflective target