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The T440 is a Single-Mode Fiber (SM) based Fiber Bragg Grating (FBG) based Packaged Displacement Sensor for use in environments from -20°C to +60°C and waterproof to 5 Bar.

Available in a wide range of optical specifications. Packaged to eliminate influences from the ambient environment. Ready for direct mounting steel construction exhibiting excellent wavelength to displacement linearity. Calibration service available upon request. The full-scale (FS) accuracy and precision specifications take into account any hysteresis, non-linearities, and the repeatability of the sensor. The T440 sensor handling and installation is fast, easy and intuitive. Delivers the advantages inherent to FBG based sensors. Immune to lightning and electromagnetic interference (EMI). Rugged construction. T440 series Displacement Sensors are fabricated using licensed and proprietary state-of-the-art laser manufacturing technologies and product designs. The sensor packaging described herein represents the most popular configuration and can be customized.

Key Features

Displacement and temperature linearity. The unibody 430 design for both displacement and temperature measurements uses precision-made FBGs written into the fibers’ core for producing a transducer configuration of high linearity, resolution, accuracy, and precision. SLSR & BW options.T440

Absolute temperature sensor included. The T430 displacement sensor includes an actual second absolute FBG temperature sensor embedded in its construction and serving as both a precise temperature compensator and as an independent absolute temperature sensor.

Zero displacement level is adjustable during installation. Field adjustable range between -40mm to +40mm and 0 to 80mm to the application requirements.

Ready for multiplexing in star architecture. Well suited for projects that include the need to monitor displacement at more than one location, using the same monitoring instrument channel. Provided as single connectorized sensors or in ready-to-install star networks of various lengths and with a flexible number of sensors.

Multiple installation options. The T430’s brackets are typically installed using welding, mounting screws, or by chemical (glue) bonding. Sensors have M6x0.5 & M16x1.5 threads for mounting.T440

Low cost and field-proven. For demanding projects that require both low cost per sensing point and stable operation for long term. Extensively used in projects measuring dilations, soil and other materials settlements, rock movement and crack monitoring, and as borehole extensometers, since 2012.

The T440 Displacement Sensor consists of a stainless steel sensor housing and an extension rod:


Welding is the primary recommended method for achieving a long-term stable bond between the monitored structure and the T440 brackets. It takes 5-10 minutes.

Tools: (1) TS900 or equivalent welder, (2) FBG interrogator, (3) Custom Mounting Brackets (not included with the sensor due to many possible designs, depending on the circumstances of each target installation in the field.

Surface preparation for welding: Regardless of the installation method, it is advisable and in some cases even necessary to properly treat the surface to which the sensor should be applied. This process includes mechanical cleaning of the surface using abrasive materials and removing any paint, rust, debris or similar imperfection from the surface. Chemical treatment of the surface is advised 20min before the installation to avoid of creation of oxide layers on the mechanical treated surface. We recommended cleaning with Loctite 7061 or 7063.

Installation Tips: Avoid extending the rod over the maximum range. Avoid exposing the sensor to temperatures above the maximum operating range of the sensor. Avoid sharp bends and high tensile strength (pull-force) on the input cable to prevent damage to the sensor.

Welding of the sensor to the surface: Direct welding of the custom mounting brackets made for the T440 is the recommended installation method for achieving a long-term stable bond.

Alternative mechanical installation (screwing): Use two standard M8 metric screws (one at each side). These screws are not supplied with the sensor. This method could be applicable to concrete walls, to other materials, to metal structures (if spot welding is not allowed).

Alternative chemical installation (gluing): Use an adhesive that bonds the T440 brackets with the measured surface. The glue is not supplied with the sensor. The selection of the glue highly depends on the material of the surface and environmental conditions. Special curing procedures such as elevated temperature, pressure or air humidity may be required when using such adhesives.

Mounting the T440 into its custom brackets: It is recommended that the T440 sensor’s housing is first installed into the custom bracket. Then, the extension rod bracket is to be installed. It is recommended that an FBG interrogator is then used to verify the success of the installation.


Applications in Civil Engineering, Geotechnical, Energy, Industrial, Marine, and Research

Technica undertakes a rigorous development process before product release. The company is also firmly committed to continuous improvements after release to ensure performance to the highest standards, hence, specifications are subject to update without notice.

Technica Optical Components / 3657 Peachtree Rd, Suite 10A, Atlanta, 30319, USA, info@technicasa.com, www.technicasa.com

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