The intermeshed detection pattern allows very wide alignment angles while rejecting external reflections through triangulation.
This Australian technology overcomes the need to have very tight alignment tolerances as with traditional parallel beam light curtains. This is achieved by synchronising two identical "transceivers" (combination transmitter/receiver).
Each transceiver has a receive point at either end and an array of transmit points in between providing four wedge shaped detection zones which continuously check and cross check each other for optical integrity.
This also produces the "hot zones" of double density detection beams down to 10mm resolution in the upper and lower quadrants, although rated resolution is 20mm.
The Sigra light curtains are available in heights of between 360mm and 1640mm and ranges up to 30m.