Using Fiber Bragg Grating Sensors to Monitor Pavement Structures

2005 ◽  
Vol 1913 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Jian-Neng Wang ◽  
Jaw-Luen Tang
Keyword(s):  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Fiber Grating ◽  
Term Stability ◽  
Long Term Stability ◽  
Fbg Sensor ◽  
Lpg Sensor ◽  
Pavement Structures ◽  
Better Than

A new high-resolution temperature and strain sensor with fiber Bragg grating (FBG) technology was developed. The FBG sensor consists of a reference fiber grating and a grating pair scheme that could offer the potential of simultaneous measurement of strain and temperature for monitoring pavement structures. Experimental results showed that measurement errors of ±μ∈ and ±0.13°C for strain and temperature could be achieved, respectively. Feasible applications of this sensor for monitoring pavement structures were investigated. The reliability and long-term stability tests for this sensor were examined by mounting it on the surface of two kinds of specimens, asphalt and concrete, and several temperature cycles with a designed working temperature range up to 110°C were applied for at least 24 h. An electronic thermocouple and a long-period optical fiber grating (LPG) sensor with similar function were used to compare the performance. Small root-mean-squared temperature variations (better than 1°C) and excellent long-term stability (within 2%) were obtained. The maximum variations in temperature for 48 h were only 1.94% and 2.32% for asphalt and concrete specimens, respectively. Results indicated that although the performance of this FBG sensor was comparable with that of the conventional thermocouple, its long-term stability was four times better than its counterpart, the LPG sensor. This type of simple and low-cost fiber-optic sensor is expected to benefit the developments and applications of new paving materials, mix design procedures, or the enhancement of pavement management systems.

scholarly journals Development of regenerated fiber Bragg grating sensors with long-term stability

2016 ◽  
Vol 24 (19) ◽  
pp. 21897 ◽  
Author(s):  
Mert Celikin ◽  
David Barba ◽  
Binod Bastola ◽  
Andreas Ruediger ◽  
Federico Rosei
Keyword(s):  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Term Stability ◽  
Long Term Stability ◽  
Fiber Bragg Grating Sensors

scholarly journals Irradiance Observations from the UARS/SUSIM and ATLAS/SUSIM Experiments

1994 ◽  
Vol 143 ◽  
pp. 72-72 ◽  
Author(s):  
Guenter Brueckner ◽  
Linton E. Floyd ◽  
Paul A. Lund ◽  
Dianne K. Prinz ◽  
Michael E. Vanhoosier
Keyword(s):  
Solar Spectrum ◽  
Daily Basis ◽  
Spectral Irradiance ◽  
Reference Channel ◽  
Term Stability ◽  
Long Term Stability ◽  
Solar Uv ◽  
Solar Ultraviolet ◽  
Better Than

The SUSIM (Solar Ultraviolet Spectral Irradiance Monitor) on board the UARS (Upper Atmosphere Research Satellite) has measured the solar UV output from 120 nm to 400 nm on a daily basis since October 1991. A reference channel records a solar spectrum semi-annually only to reduce the instrument degradation of this channel and to provide long-term stability marks. Four deuterium lamps are used at monthly, semi-annual and annual intervals to provide long term calibration of the instrument. A preliminary analysis of the long term stability of SUSIM-UARS indicates that the precision of the instrument should be better than a few percent. The repeatability of two scans is better than 0.2%. A simplified SUSIM instrument is flying on NASA’s ATLAS Spacelab missions anually to provide calibration points for the SUSIM-UARS.

scholarly journals 1996–2017 GPS position time series, velocities and quality measures for the CORS Network

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jarir Saleh ◽  
Sungpil Yoon ◽  
Kevin Choi ◽  
Lijuan Sun ◽  
Richard Snay ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Term Stability ◽  
Long Term Stability ◽  
Velocity Models ◽  
Daily Data ◽  
The Us ◽  
Global Positioning ◽  
Position Time Series ◽  
Better Than

Abstract The CORS network is a volunteer-based network of Global Positioning System reference stations located mainly in the US and its territories. We discuss the most recent comprehensive reprocessing of all GPS data collected via this network since 1996. Daily data for GPS weeks 834 through 1933 were reprocessed leading to epoch 2010.0 coordinates and velocities of 3049 stations aligned to IGS14. The updated realization of the US National Spatial Reference System derived in this work has been in use since late 2019. As a validation of the results, the derived velocity field is compared to several other solutions and to three regional geophysical and geodetic velocity models. These comparisons uncovered unstable stations which move differently than the regional kinematics around them. Once these are ignored, we estimate the horizontal and vertical stability of this updated realization to be better than ∼0.3 and ∼0.6 mm/year, respectively. We use the position residuals and estimated uncertainties from this reprocessing to derive long-term stability measures for all active stations serving longer than 3 years. These measures exposed ∼60 CORS with the poorest long-term stability, which have been consequently excluded from serving as mapping control.

scholarly journals An ultra-high-stability four-axis ultra-high-vacuum sample manipulator

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
Marcus Agåker ◽  
Carl-Johan Englund ◽  
Peter Sjöblom ◽  
Nial Wassdahl ◽  
Pierre Fredriksson ◽  
...  
Keyword(s):  
High Stability ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Design Parameters ◽  
Light Weight ◽  
Term Stability ◽  
Long Term Stability ◽  
Rotary Seal ◽  
Better Than

A report on a four-axis ultra-high-stability manipulator developed for use at the Veritas and Species RIXS beamlines at MAX IV Laboratory, Lund, Sweden, is presented. The manipulator consists of a compact, light-weight X–Y table with a stiffened Z tower carrying a platform with a rotary seal to which a manipulator rod holding the sample can be attached. Its design parameters have been optimized to achieve high eigen-frequencies via a light-weight yet stiff construction, to absorb forces without deformations, provide a low center of gravity, and have a compact footprint without compromising access to the manipulator rod. The manipulator system can house a multitude of different, easily exchangeable, manipulator rods that can be tailor-made for specific experimental requirements without having to rebuild the entire sample positioning system. It is shown that the manipulator has its lowest eigen-frequency at 48.5 Hz and that long-term stability is in the few tens of nanometres. Position accuracy is shown to be better than 100 nm. Angular accuracy is in the 500 nrad range with a long-term stability of a few hundred nanoradians.

Research on Fiber Bragg Grating Sensing Technique for Cable Tension Monitoring of Suspension Bridges

2013 ◽  
Vol 368-370 ◽  
pp. 1391-1395 ◽  
Author(s):  
Xing Jun Lv ◽  
Xue Feng Zhao ◽  
Long Wang ◽  
Hao Dong ◽  
Yan Feng Zhu
Keyword(s):  
Epoxy Resin ◽  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Suspension Bridges ◽  
Sensing Element ◽  
Long Distance ◽  
Cable Tension ◽  
Fbg Sensor ◽  
On Line

In order to realize long-distance, long-term and on-line cable tension monitoring of suspension bridges, a novel sensor has been designed based on Fiber Bragg Grating (FBG) sensing technique, which comprises of fixtures of the sensor as well as FBG, micro-spring and epoxy resin made large gauge sensing element. Further, following the calibration test for the designed FBG sensor, research on the calibrated sensor for monitoring the cable tension was carried out, whose result shows that, featured by the simplicity of operation and the accurate monitoring data, the designed FBG sensor is capable of monitoring the cable tension of built suspension bridges.

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