Photoelectric sensors are widely used and developed rapidly, mainly because it has the following features: Long detection distance If the shooting type to retain more than 10m detection distance, can achieve other detection means (magnetic, ultrasonic, etc.) can not be detected. Less restrictions on the detection of objects Since detection and detection of shading and reflection are the principal components of detection, it does not limit the detection of objects to metallic materials such as proximity sensors. It detects almost any object such as glass, plastic, wood, and liquid. Short response time The light itself is high-speed, and the circuitry of the sensor is made of electronic parts, so it does not contain mechanical working time and the response time is very short. High-resolution High-level design techniques can be used to focus the light beam on a small spot, or to form a special light-receiving optical system to achieve high resolution. Can also detect small objects and high-precision position detection. Non-contact detection is possible The detection of objects can be achieved without the need of mechanical contact, and thus the object and the sensor are not damaged. Therefore, the sensor can be used for a long time. Can achieve color discrimination The reflectance and absorptance of light formed by detecting an object vary depending on the combination of the wavelength of the light to be projected and the color of the detected object. With this property, the color of the test object can be detected. Easy to adjust In the type of projection of visible light, the projected light beam is visible to the eye, facilitating the adjustment of the position of the detected object.