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Sensors 2014, 14(4), 6797-6805; doi:10.3390/s140406797
Article

Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array

1,2,* , 1
 and 2,3
Received: 3 December 2013; in revised form: 25 March 2014 / Accepted: 28 March 2014 / Published: 14 April 2014
(This article belongs to the Special Issue Magnetic Resonance Sensors)
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Abstract: A three-magnet array unilateral NMR sensor with a homogeneous sensitive spot was employed for assessing aging of the turbine oils used in two different power stations. The Carr-Purcell-Meiboom-Gill (CPMG) sequence and Inversion Recovery-prepared CPMG were employed for measuring the 1H-NMR transverse and longitudinal relaxation times of turbine oils with different service status. Two signal components with different lifetimes were obtained by processing the transverse relaxation curves with a numeric program based on the Inverse Laplace Transformation. The long lifetime components of the transverse relaxation time T2eff and longitudinal relaxation time T1 were chosen to monitor the hydraulic fluid aging. The results demonstrate that an increase of the service time of the turbine oils clearly results in a decrease of T2eff,long and T1,long. This indicates that the T2eff,long and T1,long relaxation times, obtained from the unilateral magnetic resonance measurements, can be applied as indices for degradation of the hydraulic fluid in power station turbines.
Keywords: three-magnet array; unilateral magnetic resonance; turbine oils; power station; aging accessment; T2eff,long; T1,long; rejection standard three-magnet array; unilateral magnetic resonance; turbine oils; power station; aging accessment; T2eff,long; T1,long; rejection standard
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Guo, P.; He, W.; García-Naranjo, J.C. Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array. Sensors 2014, 14, 6797-6805.

AMA Style

Guo P, He W, García-Naranjo JC. Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array. Sensors. 2014; 14(4):6797-6805.

Chicago/Turabian Style

Guo, Pan; He, Wei; García-Naranjo, Juan C. 2014. "Degradation of Phosphate Ester Hydraulic Fluid in Power Station Turbines Investigated by a Three-Magnet Unilateral Magnet Array." Sensors 14, no. 4: 6797-6805.


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