Five Things You Should Know About Photoelectric Sensors

1. Five Things You Should Know About Photoelectric Sensors

2. Whenever an inductive sensor can’t be used for an application, the next consideration is usually given to photoelectric sensors. These sensors use a lens, a light receiver, and a light emitter for detection and can be used in many applications including automotive, material handling and for packing. While they’re useful in the detection of a number of objects, they also have their share of limitations that you should be aware of.

3. Target Colors - Photoelectric sensors are color sensitive although the level of sensitivity depends on the model of the sensor. Ultrasonic sensors can detect both colored and clear objects but will not differentiate between colors. Color sensors are able to detect colored targets and can be set to differentiate up to three different colors. Background suppression sensors don’t have a color limitation and clear object sensors can only detect targets that are transparent. • Temperature Sensitive - All sensors are temperature sensitive so it’s important that you select photoelectric sensors based on the application. Fiber-optic cables can be used with high-temperature reflectors and stainless steel sheathing for high-temperature applications. Photoelectric sensors come as high-temperature or standard models. Using them with high-temperature products will allow you to use them reliably in environments of up to 482 °C (900 °F).

4. Options of Light Sources - Light is a key aspect in the application of photoelectric sensors. These sensors come with unique light source requirements depending on the application. Laser light sources are necessary where objects are very tiny while LED lights, which are the most popular, are used for larger targets as they offer a wider light spot. You should excersise caution and not look directly into the light although Class 1, Class 2 and LED light sources are said to be eye safe. • Using Multiple Sensors - Using multiple photoelectric sensors and placing them in close proximity with one another can cause errors (cross talk) in the output. What happens is that one sensor is likely to confuse its output with that of another sensor. To overcome this, it’s advised that use models that have built-in cross-talk protection, or models operating at different frequencies in applications that require the sensors to be placed near each other. In other applications you can simply give more distance between the sensors in your setup.

5. Low Maintenance - As expected, the lens in capacitive proximity sensorsorInductive Proximity Sensorswill become dirty if their application is in a dirty environment. Different models require varying amount of regular cleaning and maintenance for proper operation. Thru beam models for instance have a high gain which allows light to burn dust and dirt and so may require less maintenance. On the other hand, ultrasonic sensors lack lenses and therefore are the best for use in dirty environments.

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