| 摘要 |
<p>A method and device to navigate excavation towards a target buried in an excavatable material, for example excavation near an underground pipeline by excavation equipment. The device generally comprises indicating material arranged to be buried in the ground in proximity to the target. The indicating material is arranged to be frangible for permitting a portion of the indicating material to be removed from a remainder either by tearing, separation at separated sections or separation at perforated lines of severance. Different visual proximity indicators on the indicating material cause different sections of the indicating material to be visually distinct from one another corresponding to different degrees of proximity to the target. In use, the indicating material is placed in the ground and excavation towards the target results in portions of the material being removed. Proximity is indicated by associating which section a removed portion of the indicating material corresponds with. The proximity indicators may comprise use of varying colour, scaled indicia or other suitable notation.</p> |
