The Strain Gauge Set mechanically measures strain in masonry-type materials or in structural components under load, relative displacements in structures, opening or closing of cracks, shrinkage of concrete block during drying, and similar applications. The anodized aluminum alloy instrument frame adjusts for measuring at 2, 4, 6, 8, or 10in spacing (5, 10, 15, 20, 25cm for metric) of Punch Bar and Invar Master Bar used. Brass inserts are mounted in specimen at selected spacing to hold stainless steel Contact Seats, threaded in place in the inserts. Hardened steel Contact Points mount in strain gauge frame for positioning in Contact Seats for measuring strain on dial indicator. Model HM-240 indicator has 0.0001in (0.002mm for HM-240F) graduations, maximum travel of 0.4in (10mm), and 0.3in (7.6mm) range of strain measurement. Digital Model HM-240D is switchable to measure to 0.0001in or 0.001mm and has a data output interface. Battery life is 5,000 hours.
Strain Gauge Set includes strain gauge dial indicator, eight brass Inserts, two Contact Seats, two mounted Contact Points and a wooden storage case. Case includes slot for Invar Master Bar Accessory and Punch Bar Accessory, not included, but required—order English or metric as needed. Master Bar has stainless steel seat inserts to check gauge space settings. Punch Bar has one fixed point and one moveable point, and is used for accurately locating brass Inserts in the specimen.