This content introduced VSPECT® (spectral analysis) as an improvement over the traditional time-domain approach to reading vibrating-wire sensors. VSPECT improves immunity to external noise, provides better precision, and gives useful measurement diagnostics. These benefits result in measurement confidence and cost-savings throughout the life of a project due to less time spent post-processing data. VSPECT has been validated in the field with the AVW200 vibrating-wire analyzer module, the CR6 datalogger, the GRANITE VWIRE 305 vibrating-wire analyzer, the CRVW3 vibrating-wire datalogger, and the VWAnalyzer vibrating-wire analyzer. The new approach has been successfully applied in large and small monitoring projects across the globe, and it was key to the success of the two bridge projects previously described—improving measurement precision, providing diagnostics to extend the useful life of the sensors, and eliminating noise as a factor in vibrating-wire measurements. As a field-proven technology with clear theoretical support, VSPECT is a major step forward in vibrating-wire measurement technology and should replace the traditional time-domain approach.
For more information, refer to the VSPECT technology brochure.
The dynamic vibrating-wire measurement technique is protected under U.S. Patent No. 8,671,758, and the vibrating-wire spectral-analysis technology (VSPECT®) is protected under U.S. Patent No. 7,779,690.
The content in this resource is a reprint from an article written by Ken Stevens, Larry Jacobsen, Tom Weinmann, and Gray Mullins and was made possible from the support of the Louisiana Department of Transportation and Development, MTI Joint Venture, CTLGroup (Technical Specialists Jaimy Juliano and Igo Kirin), the Minnesota Department of Transportation, and the University of South Florida.
Stevens, K., Jacobsen, L., Weinmann, T., and Mullins, G. (2009). “Improving Vibrating Wire Noise Immunity using Spectral Analysis,” Conference Proceedings Fatigue and Fracture in the Infrastructure - Bridges and Structures of the 21st Century, July 26-29, Philadelphia.