METHOD OF DETERMINING EXTENSION IN ONE DIRECTION IN AN OBJECT BY MEANS OF AN EXTENSOMETER, THE APPLICATION THEREOF, AND SUITABLE EXTENSOMETERS

摘要

The invention concerns a method of determining extension in one direction in an object (12) by means of an extensometer with two limbs (3). Both limbs are connected at one end to a hinge (7), can move in the plane, and are connected at the other end to the object (12), so that the limbs (3) are forced apart by the extension. According to the invention, the extension is aligned to be roughly parallel to one surface of the object (12) between the other ends of the limbs (3). The invention further concerns the application of the method, for example for monitoring a crack (13) in the object (12), as well as an extensometer for carrying out the process. The extensometer is preferably a capacitance extensometer with two capacitor plates (1, 2) configured essentially in parallel, with one capacitor plate (1, 2) on each limb (3). The extension is determined by measuring the capacitance of the capacitor system formed by the capacitor plates (1, 2).