KV Series
Crack Gages

Summary
Bonded to the cracked part of a structure or material (or a part of such material where a crack is predicted to develop), the KV series gages measure the developing length and velocity of the crack.
Different from usual strain gages, the grids of the KV series gages are cut along with crack development, resulting in resistance change.
Features
• Progress and developing velocity of the crack are electrically obtained.
• Applicable to both flat and curved surfaces.
• Resistance change vs crack length is virtually linear.
• Dedicated adapter enables use of a conventional strain amplifier.
• Extremely simple and convenient compared with the conventional optical method.
• Allows 2 trigger wires each in front of and behind the grid (KV-5C) to be used for automation of measurement.
Major Properties
Materials Resistive element | CuNi alloy foil |
---|---|
Materials Base | Paper base + phenol-epoxy |
Operating temperature in combination with major adhesives after curing (°C) | CC-33A CC-36 PC-600 |
Operating temperature in combination with major leadwire cables (°C) | ー |
Self-temperature-compensation (°C) | ー |
Applicable linear expansion coefficients (×10-6/℃) | ー |
Strain limits at normal temp. (approx. %) | ー |
Fatigue lives at normal temp. (times) | ー |
Products table
All display
KV Crack Gages

5 gages/pkg
Model | Dimensions (mm) | |||
---|---|---|---|---|
Gage(Grid) | Base | |||
Length | Width | Length | Width | |
KV-5C | 30 | 5 | ||
KV-25B | 42 | 32 |
Remarks
Applicable Adhesives: CC-33A, CC-36, PC-600
Adapter: KVA-1A (Optional accessories)
Dimensions: 35 x 20 x 15 mm