PROBLEM TO BE SOLVED: To facilitate the adjustment of a ground surface position of a lid by advancing and retracting a lid frame of a water measurement instrument box freely in the vertical direction by screwing it. ;SOLUTION: A water measurement instrument box 1 is finished to the dimension at which its whole shape becomes substantially truncated cone and consists of an upper frame 2, a lower frame 3, a lid frame 4, and a lid 5 provided in the lid frame 4 in such a manner that it can be opened and closed freely. The lid frame 4 consists of a screw cylindrical body which is screw-fitted with a screw piece part 11 of the upper frame 2, a lid supporting frame fixing ring 19, and a lid supporting frame 20. Moreover, the lid 5 is fitted in the lid supporting frame 20 through a packing 21 in such a manner that it can be opened and closed freely. For example, if the length of a screw piece part of a fitting cylindrical part is 300mm, a position of the lid 5 can be adjusted in the vertical direction in a scope of 200mm. In this way, the lid frame 4 is advanced and retracted for the upper frame 2 by screwing it to adjust the position of the lid 5 vertically, perform minute adjustment for floating of the water measurement instrument box 1 due to freezing force and the adjustment for vertical fluctuation of the ground due to freezing, and match the lid 5 with the ground GL through a year.;COPYRIGHT: (C)1997,JPO
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