The T290 is a Single-Mode Fiber (SM) based Fiber Bragg Grating (FBG) embedded in a bolt, yielding a commercially packaged Bolt Strain Sensor for measuring the tension in fasteners used for joining the components of a structure in environments from -40°C to +85°C.
Integrated into a small recess bored and threaded into the center of the head and shank of a bolt, rivet, stud, screws. Available in a wide range of optical specifications. The accuracy and precision specifications take into account any hysteresis, non-linearities, and the repeatability of the sensor. The T290 sensor installation is fast, easy, intuitive. Delivers the advantages inherent to FBG sensors. Immune to lightning and electromagnetic interference (EMI). T290 series Surface Strain Sensors are fabricated using licensed and proprietary state-of-the-art laser manufacturing technologies and a patented product design.
The sensor packaging described herein is the most popular configuration and can be customized. The T290 design consists of two precision-made FBGs written into the fibers’ core and packaged to detect strain and temperature for producingg a transducer configuration of high linearity, resolution, accuracy, and precision. Each Bolt Strain Sensor is pre-strained so that it can measure both compression and expansion forces within the fastener. Well suited for projects that include the need to monitor fastener strain and temperature at one or many locations. Provided as single-ended connectorized sensors ready to be multiplexed in a star architecture with various pigtail lengths and with a flexible number of sensors to be monitored. The T290-BCI “Bolt Core Insert” option allows it to be installed into the fasteners (bolts, rivets, studs, screws) by the customer with virtually no effect on the tensile strength of the respective fastener as long as the fastener OD > 12.5mm and its shank length is such that the bottom of the Insert terminates above the threads of the bolt.