Strain gauges are very popular for a variety of applications. They are particularly suited to measuring mechanical loads on structures as well as making geotechnical measurements, both applications related to pipeline monitoring in the oil & gas industry. You can also use strain gauge measurement systems to measure a pipeline's operational parameters, such as the pressure of the transported medium, and to prevent failures of a pipeline installed in landslide areas. In this application, you would use strain gauges observe stress on the pipeline in critical areas to detect displacement or deformation that may cause the pipeline to fail.
When monitoring pipeline integrity, the measurement system must be completely trustworthy. All business and production processes are vitally important and need to meet all the required regulations.
While strain gauges are very sensitive, and provide stable output signals with good long term performance, using them effectively requires knowledgeable personnel with a lot of practical experience. In addition, the instrumentation and cabling can be complex, and each strain gauge must be individually calibrated.
To overcome these disadvantages, some users are turning to fiber optic sensors. HBM, a worldwide manufacturer of sensors and transducers, data acquisition and software, has developed a pipeline monitoring solution using fiber optic strain sensors, called Bragg grating strain sensors. Fiber optic technology has a number of advantages over conventional strain gauge technology, including:
- Simpler wiring
- No calibration
- High resistance to alternating loads and high strain
- Excellent fatigue behavior
- Insensitivity to electromagnetic interference, including lightning strikes and other interference sources that may create a high-potential electric field
- Usable in a potentially explosive environment with no special wiring
These advantages make them a good fit for many applications, including:
- Monitoring pipeline integrity
- Observing structural integrity of bridges and pipelines
- Experimental stress analysis of vessels and tubes
- Materials testing
- Monitoring land movement