Tell-Tales are precision gauges uses to monitor movement of a crack, horizontal or vertically on a flat surface. The monitor that consist of two plates which overlap for a part of their length. The bottom plate is calibrated in millimeters and the top plate is transparent and marked with a hairline cursor in the form of a cross.

The two pegs are removed. As the crack opens, or closes, the cursor moves relative to the calibration scale. The opening or closing of the crack is then recorded on the crack record sheet supplied.

Fixing the Tell-Tale

1. The Tell-Tale is fixed across the crack using screws and plugs and/or adhesive (sold separately)

2. Fix the Tell-Tale over the crack with the vertical 0 line on the calibration scale parallel with the crack to be monitored.

3. Ensure the plate with the engraved AVONGARD name is on the right hand side of the crack.

4. Remove the two pre-set pegs. If the crack opens or closes the cursor moves relative to the calibration scale. The opening or closing of the crack can then be recorded on the record sheet (supplied with each crack monitor)