Application
The VW embedment jointmeter is used to monitor movement at joints in mass-concrete structures such as abutments, foundations, and dams.
Installation and Operation
Components of the embedment jointmeter include a socket, a transducer housing, and a submersible VW displacement transducer. The socket is plugged and embedded in the first pour. When the forms are removed, the transducer housing is inserted through the adjacent forms and the transducer shaft is screwed to the base of the socket. The housing is then embedded in the adjacent pour of concrete.
A change in the distance across the joint causes a change in the frequency signal produced by the VW displacement transducer when excited by a readout or data logger. The readout processes the signal, applies calibration factors, and displays a reading in millimeters or inches. The initial reading is used as a datum. Subsequent readings are compared to the datum to calculate the magnitude, rate, and acceleration of movement at the joint.
Advantages
High Accuracy: The VW jointmeter provides an accuracy of 0.5% full scale and a repeatability of ±0.3 mm.
Easy Installation: The target and the transducer are installed in separate pours. The transducer housing simply screws into the target.
Accommodates Shear: The transducer is mounted on universal joints that allow approximately 10 mm of shear movement in any direction.
Temperature Measurement: The VW jointmeter is equipped with a temperature sensor.
Manual or Automatic Readings: The jointmeter connects easily to a data logger for unattended monitoring.
