A marking system may hold a container from which markers are dispensed to mark the presence or absence of an underground facility in a dig area. The container may identify a marker characteristic regarding the markers in the container. The marking system may receive activation of a trigger, dispense...http://www.google.fr/patents/US20090204238?utm_source=gb-gplus-shareBrevet US20090204238 - ELECTRONICALLY CONTROLLED MARKING APPARATUS AND METHODS
ELECTRONICALLY CONTROLLED MARKING APPARATUS AND METHODS
