In an industrial setting, safety is paramount and you’re likely to find a variety of equipment that is designed to do just that – keep you safe. A safety light curtain is designed to protect people from machinery that could otherwise injure you (or your customers), and they play an important role in many workshops, warehouses and other settings. Here’s what you need to know.
What is a Safety Light Curtain?
Starting with the basics, a safety light curtain is a photoelectric device (transmitter and receiver) made up of two or more beams spaced at different intervals that is fitted on dangerous machinery. It was first designed in 1951 by German Inventor Erwin Sick – and in the years since, the light curtain has saved many lives and stopped many injuries from occurring. Use for a number of applications, including handling equipment, textile processing, automated machinery, auto or semi-auto assembly lines, and storage machinery, light curtains reduce the need for solid guards, and they are easy to setup and maintain and offer more flexibility in workplace settings.
How Does a Safety Light Curtain Work?
The light curtains offer a protective field of varying sizes, and their design and installation are regulated to ensure they are working efficiently and adhering to safety standards.
The light curtain has two main parts:
- The transmitter sends infrared light to the receiver in sequence, such as left to right or top to bottom
- The receiver which waits for these pulses in sequence
The role of the light curtain is to scan an area around dangerous machinery, and if these pulses are not coming at the right interval, it generally indicates the presence of a human or other hazard. When this happens, the light curtain will shut the machinery down.
Some of the ways it works include:
- Person detection: prevents start-up when a person is detected in the area
- Finger and hand detection: if a human finger or hand is detected too close to the area, it shuts down the machine
- Single-sided access protection that detects a person walking into the space from a particular direction
- Multi-sided protection that detects a person walking into the space from any direction
- Material vs human detection – able to determine whether the hazard is human or otherwise
How safe the machine is, depends on how efficiently it has been set up, so it is imperative that if you or your customers are going to be using these at a workshop or warehouse, they are set up by a professional who understands the legalities. Light curtains can be set up vertically, horizontally, in an L shape or even on an angle – as long as humans and hazards cannot get over, below, behind or around the protective field.
Choosing a Safety Light Curtain
When purchasing light curtains, pay attention to the particular features, such as the distance for operation and noise resistance, the Agency (eg TUV SUD, UL(cUL), KOSHA) and the Approved Standard No. Remember, finding the right light curtain and ensuring it is set up efficiently could be a matter of life or death in the workplace, so do your research and choose wisely.