Fixing Instructions 1. Fix the Caliper Marks with adhesive about 80mm to 100mm apart on either side of the crack to be monitored. 2. The line of Caliper Marks should be perpendicular to the crack. 3. Allow the adhesive to harden thoroughly before taking the first reading. 4. The distance between the Caliper Marks is measured by locating the top caliper jaw on the inside of each Caliper Mark. Humboldt Mfg. Co. 875 Tollgate Road Elgin, Illinois 60123 U.S.A. Testing Equipment for U.S.A. Toll Free: 1.800.
