The plumb bob technique is particularly suitable for these applications because dust inside the silo neither influences the results of measurement nor the conductivity of bulk solids. Alternatively the measured values can also be transmitted to a PC equipped with a corresponding interface card. With this technology the measurement can be started comfortably from the bottom or from the office and exact values will be obtained. Thus, the measured value is verified and, at the same time, the sensing weight is returned to its starting position. When reeling up again, the revolutions are also counted. Based on the reeled-off rope or tape length, the level of the container can be calculated. The rope tension indicates if the sensing weight is still freely moving in the air or if it already contacts the material filled in. When lowering the sensing weight into the container, the tape or the rope are reeled off until the sensing weight hits on the material to be monitored. The instruments are mounted on the roof of the silo. Essentially the measuring instrument consists of an electromechanically driven reel, a rope or a tape and a sensing weight at the end. they use a lowered weight fixed on a rope. The devices of the plumb bob technology basically apply a similar measuring method, i.e. The development work was focussed on the production of a measuring instrument with all the necessary and practical functionalities for these applications at a favourable price. 1) in particular for the building materials as well as the feed and grain industries. For this reason, the UWT GmbH have developed the plumb bob system Nivobob 4000 ( Fig. Apart from this, regular bustling around in such a height – usually these silos have a height of up to 30 m – is rather risky. This plumb line is important for lining up anatomical geometries and visualizing the subject's center of balance.Depending on how often the level has to be measured, such time-consuming methods quickly become no longer viable. The device used may be purpose-made plumb lines, or simply makeshift devices made from a piece of string and a weighted object, such as a metal washer. Students of figure drawing will also make use of a plumb line to find the vertical axis through the center of gravity of their subject and lay it down on paper as a point of reference. Ī plumb bob may be in a container of water (when conditions are above freezing temperatures), molasses, very viscous oils or other liquids to dampen any swinging movement, functioning as a shock absorber.ĭetermining center of gravity of an irregular shape The early skyscrapers used heavy plumb bobs, hung on wire in their elevator shafts. A variation of this tool has the plumb line hung from the top of an inverted T shape. An A-frame level with a plumb line hung from the vertex was also used to find horizontal these were used in Europe until the mid–19th century. However, if they are mounted on a suitable scale the instrument may also be used as an inclinometer to measure angles to the vertical.Īncient Egyptians used a plumb line attached to the top outer part of a tool resembling a letter E when placed against a wall, the plumb line would indicate a vertical line. A plumb bob and line alone can determine only a vertical reference.
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