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Strain Gauges

Rebar Strainmeters (VW) | Model 4911 · 4911A

  • Model 4911 (#4 rebar) “Sister Bar” (front) and 4911A (rear) Rebar Strainmeters.
  • Model 4911 and 4911A Rebar Strainmeter components and overall dimensions.
Model 4911 · 4911A

The Model 4911 Rebar Strainmeter is designed for measuring strains in foundations, slurry walls, precast piles, caissons, bridge abutments, tunnel liners, etc. The standard Model 4911 (#4 rebar), known as the “Sister Bar,” is installed alongside structural rebar. Larger models (4911A) are available for welding directly into structural rebar. Where short-term dynamic measurements are to be made, bonded resistance (Model 3911/3911A) strain gauges can be substituted, or added.


Standard Range
3000 µε
0.4 µε
±0.25% F.S.
<0.5% F.S.
Temperature Range²
−20 °C to +80 °C
Rebar Sizes
4911 | #4 (Sister Bar)
4911A | #6, 7, 8, 9, 10, 11, 14
Active Gauge Length
4911 | 914 mm
4911A | 1105 mm

¹Accuracy established under laboratory conditions.

²Other ranges available on request.

Please Note: GEOKON maintains an ongoing policy of design review and reserves the right to amend products and specifications without notice. Various instruments are discontinued over time and replaced with new, updated models.