A Method of Extracting High Precision Point to Replace in-situ SST Data

2012 ◽  
Author(s):  
Hongmei Shi ◽  
Lingyu Xu ◽  
Cuicui Song ◽  
Xiangfeng Luo ◽  
Fei Zhong ◽  
...  
Keyword(s):  
High Precision

Ion track etching of polycarbonate membranes monitored by in situ small angle X-ray scattering

2021 ◽  
Author(s):  
Alexander Kiy ◽  
Christian Notthoff ◽  
Shankar Dutt ◽  
Mark Grigg ◽  
Andrea Hadley ◽  
...  
Keyword(s):  
High Precision ◽  
Small Angle ◽  
Selective Dissolution ◽  
X Ray ◽  
Ion Tracks ◽  
X Ray Scattering ◽  
Track Etching ◽  
Polycarbonate Membranes ◽  
Ray Scattering

In situ small angle X-ray scattering (SAXS) measurements of ion track etching of polycarbonate foils are used to directly monitor the selective dissolution of ion tracks with high precision, including...

scholarly journals In-situ observations of the isotopic composition of methane at the Cabauw tall tower site

2016 ◽  
Author(s):  
Thomas Röckmann ◽  
Simon Eyer ◽  
Carina van der Veen ◽  
Maria E. Popa ◽  
Béla Tuzson ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
High Precision ◽  
Temporal Resolution ◽  
Isotope Ratio ◽  
Mesoscale Model ◽  
Ambient Air ◽  
Model Calculations ◽  
Dual Isotope ◽  
Methane Budget

Abstract. High precision analyses of the isotopic composition of methane in ambient air can potentially be used to discriminate between different source categories. Due to the complexity of isotope ratio measurements, such analyses have generally been performed in the laboratory on air samples collected in the field. This poses a limitation on the temporal resolution at which the isotopic composition can be monitored with reasonable logistical effort. Here we present the performance of a dual isotope ratio mass spectrometric system (IRMS) and a quantum cascade laser absorption spectroscopy (QCLAS) based technique for in-situ analysis of the isotopic composition of methane under field conditions. Both systems were deployed at the Cabauw experimental site for atmospheric research (CESAR) in the Netherlands and performed in-situ, high-frequency (approx. hourly) measurements for a period of more than 5 months. The IRMS and QCLAS instruments were in excellent agreement with a slight systematic offset of +(0.05 ± 0.03) ‰ for δ13C and –(3.6 ± 0.4) ‰ for δD. This was corrected for, yielding a combined dataset with more than 2500 measurements of both δ13C and δD. The high precision and temporal resolution dataset does not only reveal the overwhelming contribution of isotopically depleted agricultural CH4 emissions from ruminants at the Cabauw site, but also allows the identification of specific events with elevated contributions from more enriched sources such as natural gas and landfills. The final dataset was compared to model calculations using the global model TM5 and the mesoscale model FLEXPART-COSMO. The results of both models agree better with the measurements when the TNO-MACC emission inventory is used in the models than when the EDGAR inventory is used. This suggests that high-resolution isotope measurements have the potential to further constrain the methane budget, when they are performed at multiple sites that are representative for the entire European domain.

scholarly journals High precision machining of a displacement sensor for helicoidal motions

2021 ◽  
Author(s):  
Zeina ELRAWASHDEH ◽  
Philippe REVEL ◽  
Christine PRELLE ◽  
Frédéric LAMARQUE
Keyword(s):  
High Precision ◽  
Fiber Optic ◽  
Geometric Model ◽  
Translational Motion ◽  
Surface Characteristics ◽  
Measurement Range ◽  
Linear Displacement ◽  
Displacement Sensor ◽  
Fiber Optic Probes

Abstract This research study presents the design and the high precision manufacture procedure of a fiber-optic displacement sensor. It is composed of two fiber-optic probes associated with a structure of a cones’ grating. The sensor is characterized by its ability to measure the linear displacement for an axis performing a helicoidal motion. This motion has been demonstrated on a high precision lathe; where the spindle provided the rotational motion, associated to a translational motion on the linear stage. This allowed to obtain the two simultaneous motions. The displacement of the translational stage is measured by the sensor in real time.Firstly, a highly precise geometric model of the reflector part for the sensor was developed. This model provided a specific geometry for the cones-assembled grating, which has been precisely manufactured. The geometric parameters and the surface characteristics of each step in the fabricated grating were both identified in situ on the lathe. The agreement between simulation and experimental results is excellent. The performances of the fiber-optic displacement sensor were identified in-situ on the lathe. The analysis of the voltage output signals from the two fiber-optic probes is used to measure the grating displacement. The unbalanced rotation due to non-centered axes was also characterized. The sensor provided a micrometric resolution, on a measurement range of more than one centimeter.

High-precision in situ measurement of speed of sound in hydraulic systems

2019 ◽  
Vol 234 (3) ◽  
pp. 299-313
Author(s):  
Nigel Johnston
Keyword(s):  
High Precision ◽  
Speed Of Sound ◽  
Pressure Transducer ◽  
In Situ Measurement ◽  
Frequency Domain Method ◽  
Hydraulic Systems ◽  
Mean Flow ◽  
Transducer Calibration ◽  
Mean Flow Velocity

An existing ISO standard frequency-domain method for measurement of speed of sound in a hydraulic pipeline is enhanced and extended in this article to include in situ measurement of pressure transducer calibration factors. Transducer mounting stresses are shown to cause variations in the calibration factors, and the proposed method can be used to eliminate these uncertainties, consequently improving the accuracy of the speed of sound. 95% confidence ranges in the speed of sound of less than ±0.1% have been achieved, and such high precision cannot be achieved by other practical methods. The method can also been extended to estimate viscosity and mean flow velocity, but accuracy is less good. Novel time-domain versions of the method are introduced. These may be valuable for real-time monitoring, and changes in speed of sound or calibration factor can be tracked with minimal delay. Some examples showing the effect of sudden aeration are presented; a sudden drop in speed of sound is apparent.

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