| 摘要 |
A portable and disposable apparatus for rapidly measuring the depth of blast holes and water levels including a disposable vessel filled with material to weight the vessel. The vessel adapted to lowered into a blast hole at the end of a cord from means to dispense the cord and record the depth at which water in the hole or the bottom of the hole, causes immediate deceleration of the vessel and the temporary and/or sustained release of tension in the cord and wherein, the cord is cut post measurement and disposed of with the vessel in the hole. |
