“The Walther Light Barriers (WLS) significantly increase process safety for pulsing applications of viscous media. The Light Barriers Type WLS are available for all Pulse Valves Type MPP and will be directly attached to the nozzle outlet. When a medium dot leaves the nozzle outlet, the light beam of the Walther Light Barrier will be interrupted. The connected evaluation unit detects the resulting drop in light intensity, evaluates and provides the information on a successful discharge of a medium dot in the form of an electrical signal.”