In the realm of industrial automation and control systems, photoelectric switches play a pivotal role in enabling non-contact detection, object positioning, and process monitoring. Among the diverse range of sensors available, the GLK18-8-200/59/161/166 photoelectric switch stands out as a robust and versatile solution designed for demanding applications. This article delves into the technical specifications, operational principles, key features, and typical use cases of this specific sensor model, providing a detailed overview for engineers, technicians, and procurement specialists.
The GLK18-8-200/59/161/166 is a cylindrical, threaded housing photoelectric sensor. The model number itself encodes critical dimensional and functional parameters. The "GLK18" typically denotes the series or housing style, with "18" often indicating an 18mm diameter barrel. The "8" likely refers to the sensing distance, which in this case is 200mm, as specified by "200". The subsequent numbers "59", "161", and "166" are usually proprietary codes defining the specific light type (e.g., infrared, red light, laser), output configuration (e.g., NPN or PNP transistor, normally open or closed), and connection method (e.g., cable or connector type). This sensor commonly operates on the through-beam (also called opposed mode) principle, where a separate emitter and receiver unit are required. The emitter projects a light beam, and the receiver detects it. An object is sensed when it interrupts this beam. This method allows for the longest sensing ranges and high reliability, as it is less susceptible to the object's color, reflectivity, or surface finish compared to reflective modes.
Key technical features of the GLK18-8-200/59/161/166 contribute to its reliability. The 200mm sensing distance is suitable for applications requiring a moderate gap between the emitter and receiver. Its cylindrical M18 housing, often made of nickel-plated brass or stainless steel, provides IP67 or higher ingress protection, making it resistant to dust and temporary immersion in water—a necessity in harsh industrial environments like packaging lines, material handling, and automotive assembly. The specific output type (defined by codes like 161/166) is crucial for integration; it determines the electrical interface with programmable logic controllers (PLCs) or other control systems. For instance, an NPN output sinks current to common ground, while a PNP output sources current from the positive supply, aligning with different regional and system standards.
Installation and alignment are straightforward but critical for through-beam sensors. The emitter and receiver must be precisely aligned to ensure the beam is correctly received. Many models, including variants in this series, feature built-in alignment indicators, often LED lights that signal the strength of the received beam, simplifying setup and troubleshooting. The stable, focused beam of the through-beam design makes it ideal for detecting small objects, transparent materials like glass or plastic films, and for applications where precise positioning is required, such as in counting, break detection on conveyor belts, or gate control.
When selecting a photoelectric switch like the GLK18-8-200/59/161/166, several application factors must be considered. The operating environment is paramount; factors like ambient light, dust, moisture, and temperature extremes can affect performance. The sensor's spectral wavelength (implied by codes like "59") determines its suitability—infrared light is less visible and good for general purposes, while red light is easier for alignment. The response time and switching frequency must match the speed of the process. Furthermore, the electrical load compatibility with the control system is essential to prevent damage or malfunction.
Maintenance of these sensors is generally minimal due to their non-contact nature. However, keeping the lenses clean from dirt, oil, or debris is important to maintain optimal sensing performance. Regular functional checks should be part of preventive maintenance routines to ensure continuous operation. In summary, the GLK18-8-200/59/161/166 photoelectric switch represents a specific, well-engineered component in automation technology. Its design balances sensing range, environmental robustness, and electrical flexibility, making it a dependable choice for engineers seeking a through-beam solution for object detection tasks in various industrial settings. Understanding its coding, specifications, and proper application ensures optimal integration and long-term reliability in automated systems.
