The Tracker is used in conjunction with the Tra-Card to create the Scratch-A-Track crack monitoring system. The Tracker is mounted to the concrete to bridge the crack and record any movement as an indelible scratch on the Tra-Card. This simple device records movement as little as .005″. While some devices can only tell you where the structure is at the time you are observing it, Scratch-A-Track tells you where it has been while you’ve been away.
You can leave the Scratch-A-Track in place in all types of weather for months at a time. The Tracker can be used over and over again.
Trackers are sold individually.
Videos (click link to view)