Model VWCM-4000 -Crack Meter
VWCM-4000 crack meters are used to measure movement across surface cracks and joints in concrete, rock, soil and structures. They consist of a sensor outer body tube and an inner free-sliding rod which is connected at the internal end to a vibrating wire sensor by a spring. At the sensor end of the outer body and the external end of the rod anchors are attached which can be fixed either side of a crack to be monitored.
A change in distance between the anchors caused by the crack opening or closing causes the inner free-sliding rod to move within the outer body which changes the tension on the spring and the vibrating wire thus altering the resonant frequency of the wire.
VWCM-4000 crack meters are installed by grouting, bolting, bonding or fixing expandable anchors to the structure to be monitored.
- Ranges 5, 12.5, 25, 50, 100, 150, 200, 300mm
- Resolution <0.025% FS
- Accuracy ±0.1 to ±0.5% FS
- Non-linearity <0.5% FS
- Frequency range 1650 – 2700hz
- Waterproof rating 16 bar