The ALGE Tri-fold Photocell RLS3c is used in sports where the it is necessary to measure the point of greatest mass is passing the finish line and not an arm or leg only, or when the exact height of an object is not known.

The ALGE Tri-fold Photocell RLS3c has three seperate photo electric cells that can be used together or independently. For athletes, all three photocells must be broken before an impulse is triggered. To measure the speed of a soccer ball, the impulse is generated when any one of the photocell beams is broken.

The rear of the photocell shown, has two cable connections, a switch to choose which mode to use and three signal strngth meters to align the photocells with the reflector.