| 摘要 |
PURPOSE:To perform efficient, repeated measurement by a method wherein compressed gas is sent from the ground surface and open/close valve is automatically made to reset condition. CONSTITUTION:An automatic reset device valve 28 having a main valve 1 vertically reciprocating through a support cylinder 14, a sub-valve 3, a squeezed cylinder 7, a disk valve 10, etc. is incorporated into a measurement pipe 21. A compressed gas (air, or N2) container is connected through tube 31 to a packer 22. When a weight 23 attached to the lower end of a cable 24 having plural number of water-level measuring electrodes is placed on an outer cylinder 18, the cylinder 18 falls down and a steel ball 16 is pushed out of cut-groove 12. This causes the main valve 1 to be opened by being pushed up by hydraulic pressure 25 at the lower part of the cylinder, and the measurement of raised water level is started. After releasing expanded contact of the packer 22, the raised water level in the measurement tube 21 is pushed down with compressed gas, and the sub-valve 3 is opened so that water is discharged to the ground surface through the packer 22, etc. Then, when the water level lowers, the sub-valve 2 is pressed to contact the main valve 1, the disk valve 10 contacts the main valve 1 and the squeezed cylinder 7, then the reset condition occurs. This allows repeated measurement with efficiency in labor and time. |
