The use of optical Fiber Bragg Grating (FBG) as a strain sensor is gaining popularity. FBG can be attached directly to the surface of a target structure such as that of concrete or steel, as a strain sensor. Or, combining with other mechanical parts or chemical coatings, FBG can be used as part of a transducer for measuring a wide variety of physical quantities that include pressure, force, displacement, relative humidity or PH values, where the designated physical quantity is converted into strain and measured by FBG.Therefore the core to the success of this technology is for the FBG to function as a strain sensor that meets the required performance. Because FBG is partially distributive, multiple FBG or FBG based transducers can be connected via a single optical fiber. For ground monitoring where it is necessary to install the sensors underground, multiple and different types of FBG based sensors may be placed in a single borehole and result in much improved quality with reduced cost. Research and field experiments have demonstrated the feasibility and potential of this technology. One or more ASTM standards would be imperative for promoting the use of FBG globally. The new standard(s) shall include means and methods related to: (1) attachment of FBG to the target material either for direct strain measurement or as part of a transducer, (2) quality assurance for the attachment of FBG, (3) requirements for field set up of the FBG sensing system, and 4) collection and interpretation of data on various physical measurable quantities.
There are no standards on FBG anywhere in the world for broad applications in strain measurements within the context of monitoring stress, displacement, pressure, temperature, pH and other parameters for ensuring the safety of utilities that carry natural gas, propane and inflammable fluids. The users of the proposed standard are: pipeline owners, operators, governmental agencies charged with pipeline safety, design engineers, contractors, and those in the supply chain of optical fiber sensing industry.
Keywordsoptical fiber, optical fiber sensor, cables, pipeline, fiber Bragg grating, installation, operation, maintenance, temperature, pressures, stress, strain, pH, single point sensor, multipoint sensor, quasi distributed sensor,
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development