Measuring dynamic movement

Moiré Tell Tales can be recorded in video easily. This provides a very quick overview of movement which might provide useful information. The video can be reviewed at reduced (or accelerated) playback rate and archived for future reference.

The video below shows an example. A small crack was noted between two rings of a brick arch. Casual observers suggested the movement was 2 to 3 mm. The gauge shows it to be moving less than 0.3mm. It also shows that the movement is linear and radial to the arch, proving that the rings are only separated near the edge of the arch, a fact that was confirmed by drilling cores to trace the crack.

Case studies of dynamic movement measurement using Moiré Tell Tales:

• Dynamic crack movement in a brick arch viaduct.
• Dynamic movement of the Humber Bridge Rocker Bearings.