Safety light curtains are also known as safety light barriers or safety light screens. These optoelectronic devices are used to detect people present in the vicinity of moving machinery. Light curtains can be used as an alternative to mechanical barriers and other forms of traditional machine guarding. Set of light curtains contains transmitter head and receiver head. A transmitter generates an infra-red light between the two heads which acts as a detection zone. A movement detected within the detection zone initials the machine stopping procedure and automatically disconnect all hazardous machinery.
To reactivate the machinery, an operator has to press reset button that is positioned outside of the danger area. Some models are equipped with an auto-reset option that automatically starts machinery once the detection zone is free of obstacles. A response time of all light curtains is just a fraction of a second, it means that no other barrier type can compare to that.
Selecting the right light curtains
Maximum scanning distance and beam resolution are 2 important attributes that determine the right device for you. A distance between transmitter and receiver can be various from 0 to 20m and the choice depends on the type of machinery that is used in conjunction with the curtain.
Beam resolution determines detection capability, light curtains with 14 mm beam resolution are able to detect small body parts such as a finger, 20 mm ones are suitable for palm detection. Beam resolution of 20 mm and above are ideal for hand, head or full body detection. Typical beam resolution values are between 14mm to even 70 mm.
The physical size of curtains is also important. Some model can be small as hand but the other ones are even 2.5 m long.
