A basic (and the original) calibrated Tell-Tale that monitors horizontal and vertical movement across a crack on a flat surface. The Tell-Tale is preset at zero with transparent tape. The tape is cut after the Tell-Tale is fixed across the crack.
 
Specifications: Applications:
 
Avongard Tell-Tales are precision gauges that consist of two plates which overlap for a part of their length. The bottom plate is calibrated in milli-metres and the top plate is transparent and marked with a hairline cursor in the form of a cross. 
Fix using screws and adhesive (not included but available as accessories). 
Supplied with full instructions and Crack Record Sheet (Replacement Crack Record Sheets can be downloaded from here). 
The Tell-Tale is fixed across the crack using screws and plugs and/or adhesive. 
The tape is then cut. 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