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Pressure Cells

NATM Style Shotcrete Stress (VW) | Model 4850

  • Model 4850-1 (bottom) and 4850-2 (top) NATM Style Shotcrete Stress Cells.
  • Illustration shows typical installation in tunnel lining.
Model 4850

The Model 4850 NATM Style Shotcrete Stress Cells* are designed for the measurement of tangential (4850-1) and radial (4850-2) stresses in shotcrete tunnel linings. The cells consist of two rectangular steel plates welded together around the periphery with a de-aired fluid occupying the space between the plates. A short tube connects the cell to a vibrating wire pressure transducer. A prestressing tube is provided for expanding the cell after the concrete has cured. Cells of this type are also used for measurements of stress in mass concrete.


Standard Ranges¹
4850-1 | 7.5, 20, 35 MPa
4850-2 | 2, 3, 5 MPa
Over Range
150% F.S.
0.025% F.S.
±0.1% F.S.
Temperature Range¹
−20°C to +80°C
L × W × H¹
4850-1 | 200 × 100 × 6 mm
4850-2 | 250 × 150 × 6 mm

¹Other ranges and sizes available on request.

²Transducer accuracy established under laboratory conditions.
Total system accuracy (pressure transducer + pressure cell) is subject to site-specific variables.

*Please Note: Models are also available (3500 Series) with semiconductor pressure transducers to enable measurement of dynamic pressures (please contact GEOKON for details).

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.