Crack opening displacement (COD) gauges are designed for fracture toughness tests (both cyclic and static) to BS 7448, ASTM E399, ASTM E561, ASTM E1290, ASTM 1820, ISO 1820, and ISO 12135 by measuring the displacement between two surfaces of a crack in a material under an applied load. This data is used to assess fracture toughness and resistance to crack propagation.
Crack Opening Displacement Gauges
2670 Series
The 2670 Series crack opening displacement gauges are compatible with all common specimen geometries, including CT, SEB, center crack, and arc shaped. Each model offers class-leading linearity, while being rugged enough to withstand the high energy release common in many of these applications, and can be used at both elevated and sub-ambient temperatures (200°C to +200°C, -328°F to +392°F).
These gauges comply with requirements of ASTM E399-09:
| Gauge Length | Max Travel | Catalog Number |
| 5 mm (0.20 in) | 2 mm (0.08 in) | 2670-130 |
| 10 mm (0.39 in) | 4 mm (0.16 in) | 2670-132 |
