scholarly journals A Self-Oscillating System to Measure the Conductivity and the Permittivity of Liquids within a Single Triangular Signal

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Sylvain Druart ◽  
Denis Flandre ◽  
Laurent A. Francis
Keyword(s):  
Measurement Errors ◽  
Loop Current ◽  
Clock Feedthrough ◽  
Dc Power ◽  
Water Glycerol ◽  
Electrical Components ◽  
And Control ◽  
System Prototype ◽  
Expected Signal ◽  
Commercial Equipment

We present a methodology and a circuit to extract liquid resistance and capacitance simultaneously from the same output signal using interdigitated sensing electrodes. The principle consists in the generation of a current square wave and its application to the sensor to create a triangular output voltage which contains both the conductivity and permittivity parameters in a single periodic segment. This concept extends the Triangular Waveform Voltage (TWV) signal generation technique and is implemented by a system which consists in a closed-loop current-controlled oscillator and only requires DC power to operate. The system interface is portable and only a small number of electrical components are used to generate the expected signal. Conductivities of saline NaCl and KCl solutions, being first calibrated by commercial equipment, are characterized by a system prototype. The results show excellent linearity and prove the repeatability of the measurements. Experiments on water-glycerol mixtures validate the proposed sensing approach to measure the permittivity and the conductivity simultaneously. We discussed and identified the sources of measurement errors as circuit parasitic capacitances, switching clock feedthrough, charge injection, bandwidth, and control-current quality.

Development of reference materials with the composition of propyl and isopropyl alcohol solutions

2020 ◽  
pp. 66-72
Author(s):  
Irina A. Piterskikh ◽  
Svetlana V. Vikhrova ◽  
Nina G. Kovaleva ◽  
Tatyana O. Barynskaya
Keyword(s):  
Reference Materials ◽  
Measurement Errors ◽  
Isopropyl Alcohol ◽  
Certified Reference Materials ◽  
Toxic Substances ◽  
Biological Objects ◽  
Margin Of Error ◽  
Measurement Results ◽  
And Control ◽  
Characteristic Mass

Certified reference materials (CRM) composed of propyl (11383-2019) and isopropyl (11384-2019) alcohols solutions were created for validation of measurement procedures and control of measurement errors of measurement results of mass concentrations of toxic substances (alcohol) in biological objects (urine, blood) and water. Two ways of establishing the value of the certified characteristic – mass consentration of propanol-1 or propanol-2 have been studied. The results obtained by the preparation procedure and comparison with the standard are the same within the margin of error.

scholarly journals Correlation Between Insulation Resistance and Temperature Measurement Error in Type K and Type N Mineral Insulated, Metal Sheathed Thermocouples

2022 ◽  
Vol 43 (3) ◽  
Author(s):  
Jonathan Pearce ◽  
Declan Tucker ◽  
Carmen García Izquierdo ◽  
Raul Caballero ◽  
Trevor Ford ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Measurement Errors ◽  
Insulation Resistance ◽  
Monitoring And Control ◽  
Type K ◽  
Reference Type ◽  
Process Monitoring And Control ◽  
Resistance Breakdown ◽  
And Control

AbstractMineral insulated, metal sheathed (MI) Type K and Type N thermocouples are widely used in industry for process monitoring and control. One factor that limits their accuracy is the dramatic decrease in the insulation resistance at temperatures above about 600 °C which results in temperature measurement errors due to electrical shunting. In this work the insulation resistance of a cohort of representative MI thermocouples was characterised at temperatures up to 1160 °C, with simultaneous measurements of the error in indicated temperature by in situ comparison with a reference Type R thermocouple. Intriguingly, there appears to be a systematic relationship between the insulation resistance and the error in the indicated temperature. At a given temperature, as the insulation resistance decreases, there is a corresponding increasingly negative error in the temperature measurement. Although the measurements have a relatively large uncertainty (up to about 1 °C in temperature error and up to about 10 % in insulation resistance measurement), the trend is apparent at all temperatures above 600 °C, which suggests that it is real. Furthermore, the correlation disappears at temperatures below about 600 °C, which is consistent with the well-established diminution of insulation resistance breakdown effects below that temperature. This raises the intriguing possibility of using the as-new MI thermocouple calibration as an indicator of insulation resistance breakdown: large deviations of the electromotive force (emf) in the negative direction could indicate a correspondingly low insulation resistance.

scholarly journals Progress in a Vacuum Weight Search Experiment

Physics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Saverio Avino ◽  
Enrico Calloni ◽  
Sergio Caprara ◽  
Martina De Laurentis ◽  
Rosario De Rosa ◽  
...  
Keyword(s):  
Vacuum Energy ◽  
Transition Energy ◽  
High Sensitivity ◽  
Layered Superconductor ◽  
Final Measurement ◽  
The Status ◽  
Search Experiment ◽  
Superconducting Sample ◽  
And Control ◽  
Expected Signal

We present the status of the art of the Archimedes experiment, devoted to measuring the debated interaction of quantum vacuum fluctuations and gravity. The method is essentially the weighing of the transition energy of a layered superconductor where the contribution of vacuum energy to the transition energy is expected to be relevant. The transition is obtained by modulating the temperature of the superconducting sample at a frequency of about 10 mHz and the expected change of weight is measured with a suitably designed high sensitivity cryogenic beam balance. In this paper, we present an overview of the experiment, discussing the expected signal to be measured, and presenting in particular the result of a prototype balance operated in our present laboratory. In the frequency range of the measurement, the sensitivity is affected mainly by seismic, thermal, sensor, and control noise. We discuss these points showing in particular the design of the cryogenic apparatus, the final balance, and the quiet seismic site that will host the final measurement.

scholarly journals Damping Performance Analysis and Control of Hybrid AC/Multi-Terminal DC Power Grids

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 118712-118726 ◽  
Author(s):  
Mingchen Gu ◽  
Lasantha Meegahapola ◽  
Khoi Loon Wong
Keyword(s):  
Performance Analysis ◽  
Power Grids ◽  
Dc Power ◽  
And Control

Image Distortion, between Unwanted Geometric Aberration and the Tool Used to Improve Observation Equipment Performance

2014 ◽  
Vol 555 ◽  
pp. 751-758 ◽  
Author(s):  
Nicolae Guzulescu ◽  
Cornel Todirică ◽  
Daniel Lăpădat
Keyword(s):  
Optical System ◽  
Measurement Errors ◽  
Optical Measurement ◽  
Image Distortion ◽  
Field Of View ◽  
Optical Systems ◽  
Object Appearance ◽  
And Control ◽  
Measurement And Control ◽  
Equipment Performance

An distortion aberration free optical system forms an orthoscopic image mean that is similar to original object, undeformed. Naturally imply that most optical systems are designed so that the image distortion is minimal, not to cause inconvenience to the user about either the object appearance – when it comes to a camera or camcorder, or the deformities that may cause measurement errors – when it comes to optical measurement and control equipment. However there are situations when distortion is desired to improve some performances of the observation optical system. In this article we present how distortion is used to increase the field of view, and also how distortion is used to optimize the field of view – resolution compromise.

Global Configuration Design of Umbilicals in Deepwater

2005 ◽  
Author(s):  
Ray Fleming ◽  
Thanos Moros ◽  
Rupak Ghosh ◽  
Kostas Lambrakos ◽  
Dave Robson
Keyword(s):  
Configuration Design ◽  
Loop Current ◽  
Global Configuration ◽  
Critical Issues ◽  
The Stability ◽  
Heave Motion ◽  
Vessel Motion ◽  
And Control ◽  
Selection Of

Global configuration design of subsea umbilical risers in deep water is a major challenge due to extreme environmental and operational requirements. The critical issues considered in design are the interference between umbilicals in the presence of strong loop and submerged current, and the on-bottom stability along with the strength and fatigue requirements. The vessel motion primarily controls the selection of the configuration, catenary or lazy wave, and the latter is an obvious choice in the presence of significant heave motion. The length and routing on the seabed ensures the on-bottom umbilical stability by dissipating the axial load through soil friction. However, the interference with other subsea components as well as the space availability can also be a governing criterion in the routing. Finally, all these design requirements must be satisfied economically from the perspective of overall cost of the project without compromising quality of the product and safety of design. This paper presents a brief outline of the global configuration design of umbilicals accounting for various design considerations. The host is a semi submersible in a water depth of 6050-ft in the Gulf of Mexico. The lazy wave configurations of the chemical injection and control umbilicals are considered for the study presented herein. The methodology of design for the global configuration is discussed considering different environmental loadings such as the 100-yr and 10-yr loop current, and 100-yr submerged current. The stability of the umbilical on the seabed is discussed on the basis of analysis results for the environmental loadings with dominant vessel motions. The phenomenon of “walking” under the influence of dynamic loading is investigated and the necessary considerations in design to prevent the umbilicals from “walking” are also discussed.

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