GeoTechnical
Instrumentation
32 Years of Proven Experience and Performance
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VIBRATING WIRE CRACKMETERS MODEL 4420 |
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This instrument is designed to measure displacement across joints and cracks in rock, soil, concrete and structural members. Grouting or bolting two threaded anchors on opposite sides of the joint and then attaching the ends of the gauge to the anchors install it. |
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The transducer uses a shaft coupled to a spring, which in turn, is coupled to a vibrating wire element. Movement of the shaft changes the tension in the spring and in the wire causing a corresponding change in its frequency of vibration. |
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APPLICATIONS |
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Use Model 4420 with Conspec's P2491 Single Input Accessor Board to connect to trunk cable for continuous monitoring and read-out of all displacement changes. |
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P2491 converts frequency reading to a digital signal for transmissions of data over long distances. |
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Historical Trend Data as well as Real-Time trend data is available at any computer station connected to the system |
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SPECIFICATIONS |
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Diameter of Shaft |
.312" (8 mm) |
Diameter of Coil |
1" (25 mm) |
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Length |
12" (300 mm) |
Weight |
.25 lb (.1 kg) |
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Standard Ranges |
1, 2, 4" (25, 50, 100 mm) |
Over-Range |
1.25 x Range |
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Resolution |
.02% Range |
Accuracy |
.1% Range |