What Is A Safety Light Curtain?


Light curtains are one of the effective tools to ensure better safety in your factory premises. They automatically interrupt the functioning of potentially dangerous devices or machinery if there is a danger to the human operator present. Light curtains are also known as light screens and optical guards. Irrespective of what they are called the light curtains ensure better safety during routine operations such as maintenance. They also offer the operator greater freedom and flexibility to work safely in an industrial environment. RS Components offers a wide range of safety light curtains to make your workplace safer.

How Do Light Curtains Work?

The mechanism behind the light curtain is quite simple. It consists of two units – a transmitter and a receiver. The transmitter consists of multiple LEDs emitting pulses of infrared light to the receiver. These pulses emit in a sequence such as top to bottom, at a specific frequency. The receiver paired with the transmitter expects these pulses in the set frequency and sequence. This arrangement eliminates or minimizes the possibility of interference from any other light source.

When an opaque object passes between the transmitter and receiver, it interrupts the sequence and frequency of the pulses received by the receiver. It triggers the safety mechanism and stops the connected machinery or device.

An obvious advantage of using safety light curtains is their self-monitoring capacity. There is an inbuilt mechanism to detect any fault in the operation, which triggers an automatic stop signal. This ensures that the device or machinery will not function until an effective safeguard is in place.

Safety Light Curtains – Point of Operation and Perimeter Control

Most manufacturers and industrial facilities use light curtains as a safety mechanism in two common situations – point of operation and perimeter control.

Point of operation – for this purpose, the users install a light curtain at the site of material handling. An example would be a light curtain under a hydraulic press to make sure that no one enters the danger zone while the machine is in operation.

Perimeter control – in this, the light curtain is used to delineate an entire working space or room. This could be something like a robotic arm or a certain space. When installed, the light curtains ensure that no person or object enters the periphery of the machine’s movement.

Advantages of Light Curtains

Light curtains have several advantages over other types of safeguards like physical barriers. One of the benefits of using light curtains is easier to access the machines. It is easier and more efficient to perform routine maintenance and semi-automatic processes that require human intervention when you have a safety light curtain installed on the premises.

Some other benefits of safety light curtains are:

  • Increased productivity due to better access to machinery
  • Better workplace ergonomics
  • Need limited space for installation or operation
  • Better visibility of the machine and operating process
  • Offers protection to anyone/anything approaching the field
  • Effective finger and hand detection

Installation considerations

While installing a light curtain, the machine’s reactivation and reset switch must be set outside the light curtain’s defined area for reactivating the machine safely. Furthermore, a light curtain should be used only for machines that are capable of stopping at any point in their operation cycle. If the device will stop only after finishing its current cycle, it is not suited for a light curtain.

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