Light guide clamping device, fiber optic sensor and production method

A sensor for measuring elongations and/or compressions of a measurement object to be monitored, comprising:

• a light guide;
• and
• a clamping device for the light guide comprising:
• a carrier structure having:
• a first securing element for securing the light guide in a first position;
• a second securing element at a first distance from the first securing element for securing the light guide in a second position, wherein the first and second positions have a first distance is in a longitudinal extension of the light guide;
• and
• an intermediate carrier having
• a first surface on which the first and second securing elements are attached in respective securing positions, and
• an opposing second surface, which can be applied to a measurement object,
• wherein a second distance of the securing positions of the securing elements on the intermediate carrier is greater than the first distance in a longitudinal direction of the light guide,
• wherein the clamping device is configured to pretension a fiber Bragg grating attached to the carrier structure in such a manner that the fiber Bragg grating detects both elongations and compressions,
• the light guide having the fiber Bragg grating, and
• wherein the securing elements together with the intermediate carrier form a converter structure having a mechanical signal amplification arrangement that is free from lever action and which is configured so that a relative change in length (ε) applied to the fiber Bragg grating is greater than the relative change in length (E) applied to the intermediate carrier.

A method for producing a sensor for measuring elongations and/or compressions of a measurement object to be monitored, comprising:

• providing a carrier structure having a first and a second securing element;
• laying a light guide between the first and the second securing elements, the light guide including a sensor element;
• securing the light guide to the securing elements;
• pretensioning the light guide by means of an elastic element arranged between the securing elements;
• and
• attaching the carrier structure to an intermediate carrier,
• wherein the securing elements together with the intermediate carrier form a converter structure having a mechanical signal amplification arrangement that is free from lever action and which is configured so that a relative change in length (ε) applied to the sensor element is greater than the relative change in length (E) applied to the intermediate carrier.