Essentials of vibrating wire load cell

Load cells are instruments that monitor and   measure the load in structural members of geotechnical projects. Load cells come in different types based on measurement technology and range.Vibrating wire load cellis one such instrument to measure force using a wire that vibrates at high frequency. The external force that is applied transforms the tension on the wire which results in frequency change.  It is a high strength steel cylinder with 3 to 6 transducers. The load cells are mainly used to measure loads in rock boats, cable anchors, tendons, and tunnel supports, pile testing, loading and pulling on trial anchors and in concrete dams among others. They are water resistant and provide long term stability even in high radiation environments.

Vibrating wire convergence meter is an instrument that detects any deformation of rock or soil masses in between two anchor points using a hook in the end of both the sides. It comes in three units that include the 2 anchor points, connecting rods of 6mm diameter and thirdly the spring tension vibrating wire transducer.  The unit comes sealed and operates at even pressure of 250psi. The spring expands when the connecting rod is pulled from the gage body. This increases the tension that is picked up by the vibrating wire. The convergence is accurately determined as the tension in wire is proportional to the extension. The meter can be operated horizontally, vertically and in inclined positions.

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Dynamics of a Vibrating Wire Load Cell in Strata Measurement

As the name suggests, a vibrating wire load cell is an instrument that uses high frequency wire mechanism for measuring load-bearing force. When the load bearing force weighs down on the instrument the resulting impact causes tension on the wire which in turn, results in a change in its frequency. This change in frequency is the indicator of the load being measured; the measurement is usually accomplished with the help of a sensor that is integrated into the instrument.

 A vibrating wire convergence meter is a vital instrument for detecting any strata movement in the tunnel roof. The meter has three essential components e.g. the hooks that need to be fastened to the anchor points of the surface being studied; the vibrating wire unit which is part of the transducer and the connector rod assembly. Such a meter is vital for studying tunnel roofs inside a mine because of the steady strata movement.

The readout box is a critical part of this meter because it will give you the result of the examination you would be carrying out. For engineers in a mine this information is necessary to plan operations wherein the safety of the miners is given top priority. 

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