KEYWORDS: Temperature metrology, Optical fibers, Signal processing, Signal detection, Optical testing, Raman scattering, Light scattering, Wavelet transforms, Scattering, Water
A distributed optical fiber temperature measurement system based on Raman scatter and optical time domain reflecting (OTDR) was used to detect and locate the leakage of water pipe. Firstly, the temperature resolution of the system and the temperature difference at the leakage point were analyzed in the paper. Secondly, the lengths of 200m sensing fiber was used to locate the leakage of water pipe, and the detection signal was processed by accumulative averaging and wavelet transform. Finally, the location of pipe leakage was identified by comparing threshold signals and leakage signals. The experimental results show that the distributed fiber optic temperature system operation was stable and can identify the water pipe leakage.The system can leak location and the positioning error was less than or equal to 1m.
Polyethylene gas pipe sample with defects was detected by the transmission THz-TDS system. Firstly, the difference of the THz time-domain waveform and corresponding frequency spectra between the defect part and non-defect part was compared. Then, the PE pipe defects were imaged by the maximum value of THz time-domain data and the frequency-domain data. The results show that the existence of defects cause obvious reduction the maximum value of the THz time-domain spectrum. The PE defects can be clearly distinguished from the non-defect part by the transmission THz images. Imaged by the THz timed-domain and the frequency-domain parameter can reveal the defects in the polyethylene gas pipe.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.