Plates move relative to each other to show amount of movement.
Tell-Tales consist of two plates which overlap for part of their length. One plate is calibrated in millimetres and the overlapping plate is transparent and marked with a hairline cursor. As the crack width opens or closes, one plate moves relative to the other and the relationship of the cursor to the scale represents the amount of movement occurring.
- Standard: For movements across cracks on flat surfaces
- Corner: For monitoring movement across internal and external corners
- Displacement: For monitoring cracks when one surface moves out of plane with the other
- Tell-Tale Plus: Weather resistant, measures to an accuracy of 1.0mm