The vibrating wire crackmeters are generally used for the automatic measurement of surface cracks in buildings, civil works or historical works, openings in the ground, monitoring of structural joints in dams, bridges or artifacts. They consist of a linear displacement sensor with full vibrating wire technology with two anchors to be fixed to the sides of the crack.
Pizzi Instruments’s crackmeters are developed for different applications and are supplied with different measuring ranges and accessories required for specific applications. Models are available with IP67, IP68 protection or totally watertight with resistance to pressures of up to 100 meters of water column or higher. The vibrating wire crackmeters can be applied on mechanical biaxial or triaxial supports to monitor deformations in 2 or 3 orthogonal directions (2D or 3D control); they can be read manually with our portable units (DEC 3000 and DEC 5) or automatically with our datalogger (CUM3000, VW Brick 2, VW Brick 8, CRio VW). They can be integrated into automatic monitoring systems with real-time monitoring of phenomena and management of local alarms and real time remote alarms.
For specific requests and needs, we develop and manufacture customized products and customized with different characteristics to standard.
- Cracks in structures or rock
- Structural Joints
- Rock mass
- Buildings of reinforced concrete or masonry
- Monuments and buildings
- Applications at great depths
Depending on the specific applications and on the measuring ranges and accuracies , vibrating wire crackmeters are available with different wire deformation amplification systems
Features and Benefits
- Simple installation
- High resolution and sensitivity
- Excellent accuracy and linearity
- High reliability
- Ideal for long-term monitoring
- Integrated temperature sensor (optional)
- Completely stainless steel
- 3D displacement monitoring accessories
The body of the instrument is made of two stainless steel tubes of different diameter so that one slides inside the other.
Inside the two cylinders is a harmonic steel wire, the ends of which are connected, through an amplification system, to the head of the two tubes. The sliding of the two tubes causes a lengthening or a shortening of the wire which consequently varies its own frequency of vibration. As the two ends of the instrument are fixed on the two points whose variation in distance is being measured, the elongation of the wire will be proportional to the variation in distance between these points.
The standard version has a degree of protection IP67. A special version , completely sealed and with resistance to 10 atm, is also available.
|Sensor of temperature||Integrated (if requested)|
|Range||0÷5mm, 0÷10mm, 0÷25mm, 0÷50 mm, other on request|
|Accuracy||± 0.2% f.s.|
|Linearity||< ±0,2% f.s.|
|Resolution||< 0,02% f.s.|
|Frequency Range||500 Hz ÷ 1000 Hz|
|Inner Rod||Harmonic Steel|
|Anchoring Types||Dowels, threaded bars, fixtures|
|Protection||IP67 or IP68 up to 10 atm|
|Signal Cable||2 x 0,5; 3 x 0,5 with integrated thermistor|
|Max Distance to Datalogger||1000 mt|
Accessories and Related Products
|Triaxial Deformometer||Allows the mounting of 3 crackmeters for the monitoring of a crack into the three directions x,y,z,|
|Fixing Kit Axis Y||Allows the monitoring of the crackmeter for the control of the axis Y|
|Fixing Kit Axis Z||Allows the monitoring of the crackmeter for the control of the axis Z|
|Junction Boxes||Different Models for the connection to the different instruments|
|Multi-core cable||Different conductors for the connection of different sensors to one cable|
|DEC 5||Portable Readout Unit|
|DEC 3000||Portable Datalogger|
|CUM 3000||Multichannel Datalogger|
|MUX||Multiplexer for the connection of different sensors to the Datalogger|