| 摘要 |
<p>Frangible coloured marker comprises a flexible sheet or tape of pref. polyethylene, polypropylene, polyvinylidene chloride, or a fluorocarbon resin, with a continuous metal coating of vacuum deposited Al on it, protected by a coating of similar resin. The marker is placed in the trench overlying the utility when this has been buried, and is moisture- and soil-resistant; specif. it can be located by a detector.</p> |
