scholarly journals Measurement System of the Relative Humidity With Capacitive Sensor by CORECI 5000

Author(s):  
Monica-Anca Chita
Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4299 ◽  
Author(s):  
Ahmed Fendri ◽  
Ahmed Yahia Kallel ◽  
Hanen Nouri ◽  
Hamadi Ghariani ◽  
Olfa Kanoun

This paper aimed to develop a portable, low-cost, and easy-to-use measurement system for oil quality degradation assessment. The main two chemical parameters affected by frying are the total polar compounds (TPC) and free fatty acids. The system should characterize the change of chemical parameters by measuring the changes in its dielectric parameters. The dielectric parameters, relative permittivity, and conductivity are measured by measuring the capacitance and resistance of a capacitive sensor dipped in oil. The main challenges are that the corresponding changes of the capacitance and resistance are very small and the presence of stray effects. For this reason, the measurement system should be able to detect changes in capacitance and resistance with high resolution and with good immunity to stray effects. The proposed measurement system is based on the conversion of impedance to voltage and time and combining, therefore, having two measurement methods in one circuit. In this way, it is possible to measure the dielectric and resistive parameters and not only the relative permittivity as was done in previous works. The results showed a strong correlation between the chemical and electrical parameters with a coefficient of determination in the range of 0.9.


2005 ◽  
Vol 127 (2) ◽  
pp. 394-401 ◽  
Author(s):  
K. Khawaja ◽  
L. Seneviratne ◽  
K. Althoefer

Conform™ extrusion is a very versatile manufacturing process enabling the production of a wide range of extruded profiles. It is critical to maintain a precise predefined wheel-tooling gap for the efficient running of the Conform extrusion process and to maintain high product quality. However, this is a challenging task due to the hostile environment, high operating temperatures, and required accuracy. An accurate high-temperature gap measurement system for Conform extrusion machinery, using a capacitive sensing system, is developed in this study. The sensor is implemented in a copper Conform extrusion machine, and experimental results are presented, providing for the first time a detailed view of Conform Extrusion gap behavior during production. It is shown that the proposed gap-sensing and control system results in a number of advantages, including reduced machine setup times, reduced flash (waste) rates, and on-line monitoring and control of gap size. The research is carried out in collaboration with Holton Machinery Ltd., a leading manufacturer of Conform Extrusion machinery.


2010 ◽  
Vol 163-167 ◽  
pp. 1409-1413 ◽  
Author(s):  
Ji Kai Zhou ◽  
Xu Dong Chen ◽  
Jian Zhang ◽  
Xiao Wei Kan

The internal relative humidity (RH) and humidity gradients in concrete at early ages have a significant influence upon the properties of concrete, where exists a great discrepancy among the test results under different methods. By comparing and analyzing the traditional measuring methods of the RH in concrete, a new measuring method will be developed in this study, which could measure the internal RH in cement-based materials accurately, conveniently and digitally. The changing laws of the internal RH in concrete at early ages were discussed. The results indicate that the measuring results under the new developed system was more accurate than that by the predrilled hole method, while the external environment does not have any effect on the measured results obtained by using the new measurement system. What’s more, the results achieved by the new developed system approached the real RH in concrete very quickly; the RH near the surface of the specimen decreased quickly, while the RH in the center of the specimen decreased slowly, the moisture contents unevenly distributed through the various height of the specimen. Hence, there exists an obvious humidity gradient in concrete.


Measurement ◽  
2016 ◽  
Vol 94 ◽  
pp. 265-272 ◽  
Author(s):  
Kunjalata Kalita ◽  
Nipan Das ◽  
Pradip Kumar Boruah ◽  
Utpal Sarma

2020 ◽  
Vol 37 (5) ◽  
pp. 857-871
Author(s):  
Jean-Charles Dupont ◽  
Martial Haeffelin ◽  
Jordi Badosa ◽  
Gaelle Clain ◽  
Christophe Raux ◽  
...  

AbstractMeasurement of water vapor or humidity in the atmosphere is fundamental for many applications. Relative humidity measurements with a capacitive sensor in radiosondes are affected by several factors that need to be assessed and corrected. This work aims to address corrections for the main effects for the Meteomodem M10 radiosonde as a step to meet the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) requirements. The considered corrections are 1) the calibration correction; 2) a slow regime due to the slow diffusion of molecules through the sensor, especially at very high and very low relative humidity conditions; 3) the relative humidity sensor dependence on the gradient of temperature; and 4) the time lag at cold temperatures, which affects measurements in regions of strong relative humidity gradients. These corrections were tested for 26 nighttime and 25 daytime radiosondes in two midlatitude locations for which both Meteomodem M10 and Vaisala RS92 measurements were available. The results show that, after correcting for the four effects, M10 relative humidity measurements are, on average, consistent with the Vaisala RS92 relative humidity values within 2% RH at all altitudes for the nighttime launches (against 6% RH before the correction) and within 5% RH at all altitudes for the daytime launches (against 9% RH before the correction).


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