Depth sound
A depth plumb line is a measuring plumb line for determining a depth, such as the distance between the groundwater level and the top of the ground ( floor distance ). The solder is composed of a cable drum with a stainless steel cable and a subsequent draining device with centrifugal brake and the depth display together. There are different plumb bobs (plastic float, stainless steel weight) to choose from, which make it possible to determine both the height of the groundwater surface and the bottom of the measuring point .
When determining the distance from the corridor, a control lamp lights up when the water surface is reached, and the depth in relation to the upper edge of the pipe of the groundwater measuring point can be read on the measuring tape. This type of plumb line is therefore also known as light plumb bob .
It should be noted that the depth plumb bob is subject to different corrections for different plumb bobs and different pipe diameters. The advantages are that the centrifugal brake, which keeps the rope movement constant, means that no errors can occur on the part of the user during the measurement , as long as he has adhered to the apparent plumb line diameter. This means that sporadic measurement errors can almost be ruled out as the device works fully automatically. New devices also have a digital display . Disadvantages are caused by the setting options of the device, so that in the field, if a setting table is not available, the measurements can only be carried out imprecisely.
See also
swell
- Bernward Hölting, Wilhelm Georg Coldewey: Hydrogeology. Introduction to general and applied hydrogeology. Elsevier, Munich and Heidelberg 2005, ISBN 978-3827417138 .