Small machines with limited space tend to use light curtains with finger resolution (14 mm) which allow detection of smaller objects with a short response time.
Light curtains for finger protection offer the highest degree of protection and are suitable for machines where the operator works close to the hazard. Whenever space is limited and the safety distance must be short, finger detection is a good option as its resolution is about half that of hand detection and it will detect the object sooner than hand resolution will do. Consequently, this sort of light curtain is used in applications like tool stations, pharmaceutical work cells and small press machines.
Light curtains with finger resolution are available in robust housings with a profile of 42 mm x 48 mm and an enclosure rating of IP65 and IP67. The standard associated with this design is Type 4 according to IEC 61496-1 and -2 and ISO 13849-1. Protective length extends up to 1.7 meters and maximum operating range is 3.5 m. Two communication channels can be selected to avoid cross-talk between two different pairs of light curtains that may be installed next to each other.