Vibrating Wire Jointmeter is composed of socket and vibrating wire displacement sensor. 
Install the Socket in the base concrete structure and connect the vibrating wire displacement sensor, after installation, 
place the concrete. Displacement in Joint part of two concrete structure occurred, at this time, frequency becomes different depending on displacement. 
The measured frequency is converted into displacement by conversion factor.
Normally it is used to monitor the changes in joint of concrete structures such as dam, foundations, column for bridge.