How to choose a photoelectric sensor！

How to choose a photoelectric sensor
             

Photoelectric sensors are generally at least nine or more sensing mode, using two light sources, there are three package sizes, five or more detection range, and can use various combinations of installation, output and operating voltage of purchase. This creates the possibility of disturbing the candidate sensor wide variety, it makes it difficult to choose.

Photoelectric Sensor Specifications

■ Size

■ sensing mode

■ Sensing Range

■ Installation

■ Output

■ mode

■ Operating Voltage

■ source

■ Connection

■ Packaging Materials

■ Special features include:

It can handle high-speed and / or high temperature

· Logic Control

Can be computer programming

· Network compatibility

Such excess can choose two ways to narrow down: first need to consider the detection object; followed by the sensor working environment.

Packing

The first question we have to ask is: What you really want the sensor? "We are in the bottle detection, detection or cartons?" Sensors Sensor manufacturers -Banner engineering company engineer GregKnutson representation.

Optical properties and physical distance will determine what kind of sensing mode most appropriate and what kind of light source. For example, in the case of detection of monochromatic carton, it may be the use of inexpensive, light beam reflected from the carton scatter sensors.

But when the carton is colored so that the reflectivity is not the same, you can not use the above solutions. In this case, the best solution may be the use of contrast or reflective mode sensor. In this scenario, the system is to work through the shield beam. When the carton in place, the beam is blocked, so that the carton is detected. If there is no transparent box, this technique should be able to obtain reliable results. At present, several sensors can detect different heights of cartons.

Select the distance light source, such as an LED or laser plays an important role when. LED although cheaper, but because it is a high degree of scattering of light, and therefore suitable for short-distance use. Laser-focused on one point, so they can get spread farther beam. When you need to detect subtle features, good focus also important. If you need to align the fine features from a few feet away, you must use a laser.

Laser sensor many times more expensive than LED, but the difference has been dropped laser diode prices reduced. Although laser currently used is still expensive, but compared to past spending has been reduced a lot.

Environmental challenges

Another decision factor when selecting a sensor is the work environment. Some industries (such as food and automotive industries) work environment may be dirty or dangerous, or both. When handling food, humidity may be higher, and there are a lot of liquid. Processing engine or other car parts factory workshop, there may be sand, lubricants and coolants. In this case, we must consider the environmental adaptability of the sensor, if the sensor can not adapt to the environment of dirt can not be used. Such considerations also affect the required detection range, because the sensor may need to be placed outside the harsh environment of a distant location (rather than on the desired location). If the light is dirty or the signal weakens, then proactively alerting and notification is helpful.

Similar problems also affect environmental change in the size of the sensor, the size can be from more than one finger to bigger than the smaller open palm. The small size of the sensor than expensive large-size sensor, because all the parts are loaded into a higher cost small space. Light collection area of ​​the small size of the sensor is smaller, a smaller detection range and lower optical properties. These drawbacks must be overcome, so that the small size of the sensor to better match the physical space available.

Again, the sensor in the semiconductor clean room equipment used in the work environment is not bad though, but must work within a narrow space. Detecting distance is typically several inches so that the sensor is generally small. These sensors often use optical fiber to the light to import (or export) detection zone.

Installation and Prices

Another factor to consider is to install the system. Sensors typically require a box or other methods for mechanical protection. The cost of such mechanical protection of the optical sensor itself may be greater than the cost is higher, and therefore is an important factor to consider when buying. If the firm has a flexible mounting system, as well as arrangements for the protection of the installation of the sensor, the product is easier to implement, and live longer.

Prices and special laser photoelectric sensor is about $ 150 to $ 500. Like the lower package, as well as the optical properties of the standard limited (or no) external adjustment, they are each sensor has the characteristics of low-end products. The high-end products will have advanced packaging (such as stainless steel or aluminum, etc.), high optical performance and an adjustable gain, time, or other options. Low-end products for general applications, and high-end products can be used at high speeds, high temperatures or explosive and other special circumstances.

Finally, remember A sensing technology can not meet all the needs of the application, if the need to change, you may need a completely different sensor technologies. Sensor manufacturers -Pepperl + Fuchs product manager EdMyers said that if the vendor offers a variety of sensor technology in the same package with the dimensions, then go to a new method is not difficult. If so, then as your needs change, it is easy to shift from one another sensor technology sensor technology.

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