With the latest advances in industrial automation, sensors and actuators have become an essential element in just about every manufacturing assembly line. Wherever the distance, absence or presence of an object needs to be measured, a photoelectric sensor is used. There are three main types of photoelectric sensors: through-beam, reflective, and diffused. Each sensor has its own advantages and can be used in a variety of ways.
The photoelectric sensor senses the position of objects using a modulated light beam emanating from a light transmitter. The absence or presence of the target is dependent on the reflection of the light beam which is captured using a photoelectric receiver. A photoelectric sensor makes use of modulated light, usually from an LED source, which is pulsed at a specific frequency anywhere between 5 and 30 kHz. This reduces the chances of ambient light or reflective glare affecting the sensor’s performance.
Installation of photoelectric sensors
However, not all assembly lines are plain sailing for the installation of photoelectric sensors. Some manufacturing environments such as food production lines may be clean, dry and dust-free due to the levels of hygiene required. But some environments, particularly industrial ones, can be filled with hazards such as extreme heat or cold, shocks, radiation, chemical spray or sparks, and contaminants like dust particles, smoke, moisture and dirt. Examples of these demanding types of industrial environments could include automotive manufacturing, wood processing or mechanical engineering.
In addition to the risk that sensors might register false positives in such environments and cause assembly line breakdowns, quality control failures or even assembly line accidents, there are also risks posed to the longevity of the sensors themselves, necessitating replacement if they are no longer functional. All of these risks pose serious implications for the manufacturer, so it is of vital importance to ensure that the right type of sensor is installed for the application in question.
The system designer must ask the following questions prior to the purchase and installation of photoelectric sensors on the assembly line:
- What is the distance rating and sensitivity of the sensor?
- What are the ambient temperatures the sensor will usually be exposed to?
- What hazards will the sensor be exposed to?
- What contaminants will the sensor be exposed to?
- In case of breakdown on the production line, would the sensor be exposed to more extreme temperatures or any other increased hazards for longer than usual?
The next step would be to determine what preventative measures can be taken to ensure that the sensors are not exposed to damage due to hazards or contaminants:
- Use sensors with an appropriate IP rating to ensure protection of the device against water, dirt and heat
- Install the sensors at a higher distance above the assembly line target mark
- Clean the sensors regularly to avoid buildup of dirt, dust and oily residue
- Cool the sensors using air or water cooling options if possible
Bulgin's cost-effective and flexible slimline photoelectric sensor range offers a high degree of mechanical and electrical stability. The solution has been designed specifically with manufacturing automation and industrial automation sensing operations in mind. The Bulgin photoelectric sensor is a combination of reflective and diffusion beam, meaning only one sensor is required for the system as opposed to using multiple types of sensors within the assembly line. With their simple, secure and efficient design, these sensors offer a watertight and dustproof seal to any standard M5 interface. The sensors are made with highly robust stainless steel 316 casing material and can withstand a high degree of physical impact, including superior vibration and shock and bump resistance.
Product codes: SLLP3002M5, SLDP3002M5, SLLN3002M5, SLDN3002M5, SLLP4002M5, SLDP4002M5, SLLN4002M5, SLDN4002M5, SLLP3002CL, SLDP3002CL, SLLN3002CL, SLDN3002CL, SLLP4002CL, SLDP4002CL, SLLN4002CL, SLDN4002CL