VW Crackmeters

VW Crackmeters

The Model 4420 Crackmeter is intended to measure movement across surface cracks and joints. It is installed by grouting, bolting, or bonding two threaded anchors (with ball joints) on opposite sides of the crack and then attaching the ends of the gage to the anchors.

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Features & Applications
Options & Accessories


  • Proven and reliable vibrating-wire technology 
  • Excellent stability for long term measurements 
  • Spring-loaded 
  • Several mounting methods 
  • Waterproof 
  • Stainless steel construction 
  • Accepts very long instrumentation cable 
  • Built-in thermistor 


  • Cracks in concrete bridges, dams, and buildings 
  • Bridge expansion joints 


Standard Range¹ 12.5, 25, 50, 100, 150 mm
Resolution 0.025% F.S.
Accuracy² ±0.1% F.S.
Nonlinearity <0.5% F.S.
Temperature Range¹ −20°C to +80°C
Lengths³ 318, 343, 397, 559, 649 mm (transducer)
Diameter 8 mm (shaft) / 25 mm (coil)


1 Other ranges available on request.
2 Accuracy established under laboratory conditions.
3 Length dimensions are in mid-range position.


Options & Accessories

  • Grouting, bolting, or bonding mounting systems 
  • Fiberglass extension rod 
  • Displacements options up to 3.0 in (7.6 cm) 
  • Medium- or heavy-duty instrumentation cable