| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an instrument which can measure transparency highly accurately without being affected by waves. <P>SOLUTION: A transparency measuring instrument 1 comprises: a sign plate 2, which is nontransparent and has a plate shape, for measuring water transparency; ropes 10, 11 for suspending the sign plate 2; a weight 8 which is attached under the sign plate 2. The sign plate 2 is provided with water passing holes 5, 6, 7 which penetrate upper and lower surfaces thereof. When the sign plate 2 and the weight 8 are lowered into water, the water passes through the water passing holes 5, 6, 7 towards the upper surface side of the sign plate 2, reducing water resistance acting upon the sign plate 2. Thus, the sign plate 2 can be vertically lowered into water while keeping the horizontal posture, increasing accuracy of measuring the water transparency. <P>COPYRIGHT: (C)2012,JPO&INPIT |
