Measuring long term movement

Moiré Tell Tales can be left in place for long periods. Long term movement can then be monitored simply by occasional recording using a camera or mobile phone.

Compared with other means of long term crack monitoring, Moiré Tell Tales have some significant advantages.

• Read movements of as little as 0.1mm in two directions.
• No additional equipment required to read the tell tale. Only a standard camera is needed to make a record.
• Readings of a correctly installed Moiré Tell Tale are not sensitive to the technique of the person recording.
• Records can be made from considerable distances.
• Dynamic response can be monitored using the same simple device as long term trend.

Each Moiré Tell Tale has a unique ID, encoded in a QR Code (a type of 2D bar code). Photographs of Moiré Tell Tales can be filed automatically by searching images for these codes.